New Nitrate theory

[Paul B]

I have been wondering for years why so many people have high nitrate forcing them to change large volumes of water when they have DSBs which are supposed to eliminate nitrates through anerobic bacteria.

Some people have even resorted to adding remote DSBs or constructing them very deep.
This does not help and new research explains why.
I recently read a "Sea Scope" publication written by Bob Goemans and it confirms what I have been saying for years.
DSB technology is flawed, but we never knew exactly why.
Yesterday I called Bob at his home to discuss the article.
We think of two different types of bacteria that inhabit the two zones in an aquarium. One is aerobic heterotrophs which live in the upper layer of a DSB and every other oxygenated surface in a tank. The other is Anerobic bacteria that inhabit anerobic or very low oxygen areas.
These anerobic bacteria (we thought) are the ones that convert nitrate to harmless nitrogen gas which harmlessly bubbles out of the water.
Now we find that there is another form of bacteria that lives in close association with the nitrate reducing bacteria in deeper, less oxygenated layers. These other bacteria are also anerobic but they convert nitrogen back to ammonium. As the ammonium rises from the deeper layers it is again converted back to nitrate and diffuses into the water column.

There are not just two zones in an aquarium but three. There is aerobic or oxygen rich areas, anerobic areas which have very little to no oxygen and anoxic zones which are in between and have a small amount of oxygen. Such an area would be just under the surface of the sand or gravel (or in a slow running RUGF)
The anoxic layer with a small amount of oxygen is where the beneficial bacteria florish which convert nitrate to harmless gas.
If a tank has a large anerobic (no oxygen) area such as a DSB and a small anoxic ( or low oxygen) area, nitrate and nitrite could be converted back to ammonium, then back again to nitrate.

A quote from Bobs article
"This is referred to as the ammonification process. The continueing re processing of this ammonium produced in the lower anerobic level of the substrate, back into nitrite and nitrate in the upper reaches of the substrate, is quite feasable. With any of them-ammonium, nitrite, nitrate-leaching back into the bulk water is quite possable"

So it seems that if we want to reduce nitrate we need to have more anoxic or "low" not "no" oxygen areas. DSBs that are not very deep or gravel beds would accomplish this

[spsfreak]

Great to hear of this news\theory Paul. I too have always thought the DSB's were a source of problems from past exp. That is why I have kept BB or very SSB's in my last few tanks.

[onetrickpony]

do you think the ammonification process would apply to some of the more dense rock some use

[onetrickpony]

http://img.photobucket.com/albums/v679/ken75459/nitrocycle.gif

[PatrickJ]

I've had similar thoughts, if not identical. I think DSB can be still useful, but remote setups are ideal but not practicle in my home.

I am planning to go BB next time around with maybe some sort of carbon source denitrator in place of a DSB.

Denitrators are far more efficent than DSB and take up less space.

[Paul B]

do you think the ammonification process would apply to some of the more dense rock some use

Yes, that was also part of the article.
DSBs are OK but deeper is not better. If you can pick up a copy of Sea Scope Volume 23 which is a free pamphlet put put out by Instant Ocean you can read the entire article.

[Paul B]

This is the letter Bob just wrote back to me

Quote
"Hi Paul.
Could be those people that keep changing water to reduce nitrate don’t realize that within one to two days after a change the nitrate level returns to the almost the exact level it was before the change. The reason for that is nitrate is flowing back into the bulk water from their sandbed and live rock! Water changes are ‘not’ the proper way to reduce nitrate – getting to the root cause is the way to go and also that of understanding how those bacterium work in substrates of various kinds, depths, and porosity.
Bob"

[gwenvet]

So what's his determination of how deep is too deep? And is it dependent on how large the sand bed's particulate size is? I would imagine that you could get away with a deeper sand bed composed of larger particle size than you could with a very fine sand that would create an anoxic zone at less depth.

[IslandCrow]

That's interesting Paul. I always understood that you didn't want to go too deep in your sandbed specifically because you didn't want an anaerobic area to develop. It seems that the suggested DSB depth of 4-6" for sugar-sized sand should still hold valid, though. Although I always thought the main issue was the possibility of hydrogen sulfide being produced, it sounds like if you're indeed avoiding that anaerobic region, you're avoiding this third type of bacteria as well.

So, is this really a flaw in the DSB theory, or is it just that people are misapplying the concept?

[Paul B]

So what's his determination of how deep is too deep? And is it dependent on how large the sand bed's particulate size is? I would imagine that you could get away with a deeper sand bed composed of larger particle size than you could with a very fine sand that would create an anoxic zone at less depth.

gwenvet, he just states that we should be limiting the depth of the bed and use coarser materials, also limit live rock.

I would disagree with him about the rock but I have always said sand in a DSB is too fine, not allowing any oxygen to circulate.
I diden't know about these other bacteria that converted the nitrogen gas back to ammonium in a complete state of lack of oxygen.
The article states that we should try to get more anoxic or low oxygen areas and less anerobic or no oxygen areas.

[HumanIMDB]

Hrm...having just (last year) setup our AGA92 with 4"-5" of sugar sand in the Display and 8" in the refugium, I am going to ignore this thread until we start having problems. ;)

Paul, any suggestions on how to mitigate this issue if one already has a DSB and doesn't want to go through the hassles of removing it? :D

[Paul B]

Chris, according to this research, DSBs are too deep, allowing those nitrate converters to florish. I would think reducing the substrate to about an inch and a half would do it.

UG filters also don't work but if you tweek it the proper way, they work as my tank proves.
I never believed the concept that "critters" in a DSB burrow under the sand to let in water to be treated. All "critters" need oxygen to live and none of them are going to burrow into a bed with no oxygen, it just aint going to happen. It would be like me crawling into a burning building for no purpose when I can stay up here where I can breathe.
It seems that reducing oxygen, not entirely eliminating it, allows these beneficial bacteria to florish while not allowing the bacteria that re convert nitrate to ammonium to be converted back to nitrates to live.
I am not a chemist or researcher, I am a hobbiest like the rest of you. But I do have an old tank with no DSB with almost no nitrates where I hardly ever have to change water and I never change it because of nitrates.
Don't change anything because of this research, come to your own conclusions. Find people with deep DSBs and see if they read nitrates.


(1) Jaubert 1989, An integrated nitrifying denitrifying biological system capable of purifying seawater in a closed circuit aquarium Bull. Inst.Oceanogr. Monaco. 5:101-106

(2) Gamble. S Goemans, B 2001, The new Wave, Aquarium Husbandry, A More Natural Approach. Weiss Organics, Ft, Lauderdale. FL

(3) www.icsu-scope.org/downloadpubs/scope21/chapter18html

(4) Boudreau B.P. Jorgensen, BB 2002 The Benthic Boundary Layer: transport process and biochemistry, Oxford University Press 2002

There are many more references but I don't want to type them all unless you really need them

[HumanIMDB]

We went with a deeper sandbed in the DT to allow for burrowing by a goby/shrimp pair and/or jawfish, otherwise we would have gone with a 1" to 1 1/2" sandbed in the DT. However, having read up on things before setting it up, we saw the "advantages" of having a DSB in the refugium. I guess we will have to see how things pan out and live with the choices we made in the beginning or remove the problem when it occurs.

That said, we'll likely move before this becomes an issue so if further research shows that the DSBs do more harm than good, that will be the time when we'll revamp our setup. :)

[MileHighFish]

This is interesting news, my 1st set up had a 6" DSB in a 60 gal tank, I had a heavy fish load for that size tank and I always dealt with nitrates WC never seamed to be an effective method to elevate the issue. I upgraded to a 100 gal, I never increased the amount of LR used, same fish etc 6'' bed and same nitrate issue that tank was up 5 years and always had 20ppm nitrate. I moved and only took a small amount of sand with me, maybe 1/2" - 1 1/2" in parts, again the same rock etc.. Within a month the tank zeroed out, at the point I started to look at friends that had nitrate issues and all ran DSB. I just moved 900 miles and still running the SSB and no nitrate issue. Since setting the 1st tank up with the SSB I hardly do WC's and the nitrates dont build up.. I went 7 months without a WC about a year ago and with a Pin Point nitrate meter I was testing at 2ppm. So I do think there is something to this new finding..

[Paul B]

Milehighfish, It would seem the new studies have some validity.
Anyone else have high nitrates with a DSB?

[davewbush]

I've been running DSB between 6 and 7 inches and my nitrates are at 0 and have been there for over a year. I did move the tank in January and the nitrates went up to 10ppm but fell back down to 0 after the first month.

Back in October, November, and the begening of December I got lazy but the nitrates didn't go up. I did how ever have a problem with phos levels at this time.

I test my water today and nitrates, ammonia, and phos were at 0.

[Konadog]

Interesting article Paul. This may also explain some of the "old sand bed crashes" that people talk about.

[Philwd]

<a href=showthread.php?s=&postid=14574735#post14574735 target=_blank>Originally posted</a> by Konadog
Interesting article Paul. This may also explain some of the "old sand bed crashes" that people talk about.

Can you elaborate further on your thoughts here? I run a black sand bed 4-5" but the grains are larger than a typical DSB. I also run a fuge. Never really had nitrates until ran into a bad stretch at work and let detritus build up in the sump.

[MileHighFish]

I think thats what he is saying over time and with out proper or constant attention you might have issues.

[Paul B]

Dave, I guess the theory doesen't work on every tank, what can I say? Also your DSB is very young.

Ken I feel all DSBs will crash in a number of years. Eventually the small spaces between the sand have to become completely clogged and being you can't maintain them I do not see any other result. I think ten years (which is just a guess) should do it.
(of course I could be wrong, me not being the God of DSBs)
I do not think any critters will burrow into a non oxygenated area that most likely has hydrogen sulfide.

Phil, according to the research as long as the grains are larger and some oxygen gets through you will have more anoxic zones than anerobic zones and it should be fine.

I am curious, how many people here have a DSB for five or ten years or longer? We will never know the answers to these questions unless we have an accurate count. And out of those beds, how many (if any) read anynitrates?

[Paul B]

Here is the entire article if anyone is interested, I just found it online


Try this one
http://www.instantocean.com/uploadedFiles/InstantOcean/OceanKnowledge/SeaScope/Past/SS_Vol23_Fall_2007.pdf

The last page of the article is all you really need to read, if you don't like reading :D

[davewbush]

I was thinking last night that my sand bed was young too. I will keep my eye on it see what happens. THis hobby is like every thing else, constantly changing. Thank you for the information. I too am not a DSB expert of a reef tank expert at that.

[waynem]

Thanks for the information. I just wish I had it 5-6 years ago and didn't have to figure it out myself.

Now I have some proof to my claim* that DSD are death beds, I tell people that all the time but no one ever believes me lol.

*for the last few years..only

[aquacare]

Do not forget the process of ANAMMOX: it is the anaerobic ammonia oxidation. I think in a deep sand this process will occur.

[stony_corals]

No offense, but that article is nothing more than the writer reflecting. You will not be able to control which species of bacteria inhabit your system. Even identifying them is prohibitive except for the best equiped labs. Interesting theory... but as someone who has run DSBs for long periods of time (4+ years), I always had unmeasurable NO3 using LaMotte... Interesting thoughts, but bacteria biofilms and guilds are hardy a static process.

[Paul B]

Stony_corals, I think the author said that this "may" be a cause of excess nitrates in a DSB.
Actually he states that this process is quite possable. I don't think this has to happen. But it apparently is happening in the tanks that are experiencing nitrate problems. What other cause could there be in a system that is supposed to be so efficient at controlling nitrates?
As I said, I don't have nitrates as measured by a professional lab and I don't run a DSB but there are many DSBs on here with nitrates and there should not be any.
It is just one article, you can just ignore it

[eb8919]

Very interesting article, especially for myself as i was just debating whether to go deep or shallow on my new system. My question is, how does the dsb bucket idea work that people have raved about dropping nitrates to 0. Is it to a different extreme because of the great depth, or is the bucket just a quick fix until the sand apocalypse happens? I am not that knowledgable when it comes to sand beds so maybe this is a dumb question...

[Paul B]

I think all DSBs will fail eventually but I am sure they work fine in the meantime.
I am not the person who should answer this because as you can tell, I don't like them

[moumda]

I'm using a dsb in a bucket and it's worked well for me. It's only been going 2 years so the jury is still out. I agree with Paul that it will eventually fail but the way I have it set up it's easy to take out of the system.

[Paul B]

I think buckets are the way to go. If it croaks, take it out and put in another one. That way I like them

[jenglish]

I am still reviewing the article as it is lengthy but it does not seem that new. I realize DSB systems require waterchanges or they will accumulate nitrates but doesn't a plenum or UG or BB system require them as well? I mean barring coil denitrator or ATS or some other system like that?

[Paul B]

My system does not require water changes to lower nitrates. I change water four or five times a year just to replace trace elements. If I never changed water my nitrates would stay around five as they are now.
What is the reason for a DSB if they require more water changes?

[hottuna]

Interesting , Paul.....this might explain why the people at esv used to say that their oolitic sand would denitrify just perfectly when only one inch deep...
I had a 120 back in the day with only one inch of oolitic sand...and it did denitrify-nitrates never exceeded .3ppm and I changed water in very small amts every month..(5gal)

[vermonter310]

<a href=showthread.php?s=&postid=14580253#post14580253 target=_blank>Originally posted</a> by eb8919
My question is, how does the dsb bucket idea work that people have raved about dropping nitrates to 0. Is it to a different extreme because of the great depth, or is the bucket just a quick fix until the sand apocalypse happens?

No DSB expert but just in reading this short(for the moment) thread it would seem to me that the reason RDSB's work quickly is because they would quickly develop the low oxygen areas, which appears to be the effective portion. over time, like the DSB's in a display tank, due to buildup of whatever kind, they would develop the no oxygen areas and begin to reintroduce the nitrates into the water collumn.

but like I said, just my $.02 after reading this short thread. I'm in the process of setting up my tank (been down for about 3years) and been researching this subject a lot.

[wayne in norway]

I don't want to seem a smart arse but this is hardly ground breaking news is it? FWIW I use a medium lengh dsb with a stack of flow over the top and have had zero nitrates for a while now, and it looks pretty stable. The amount of flow in combination with the grain size is the driver on how deep you need to go to get from a (useful) low oxygen zone to an (unhelpful) zero oxygen zone.
I haven't seen numbers on how much ammonium makes it back up thro' the sand bed without being reoxidised. I guess it's presence reduces the need for the bacteria to use/remove nitrogenenous compounds from the water in the 'water' part of the display, and so reduces it's effectiveness as a secondary effect.
FWIW I would think an inch and a half is a bit shallow - if you plough the papers on the subject you'll find there's quite a bit of flow, movement of water and light solids thro' the sand bed at that sort of depth.

[moumda]

eb8919: Here is the article by Calfo on dsb in a bucket. This is also how I set mine up in my 70 sps tank.
http://reefcentral.com/forums/showthread.php?s=&threadid=595109&perpage=25&pagenumber=1

[Luigi]

Just FWIW you are confusing the term anoxia, this means NO OXIGEN. What you mean is HYPOXIA this means low oxigen.

And I have been using DSB 10cm deep for at least 5 years and my nitrates stay near cero. So probably the harmful depth must be deeper...

[Paul B]

Just FWIW you are using bad the term anoxia, this means NO OXIGEN. What you mean is HYPOXIA this means low oxigen.

Luigi, I think you are correct but I was just quoting from the article.

As for bucket DSBs working, I think any DSB will work for a few years. I don't feel 5 or even 10 years is long enough. Almost all of my fish live longer than that and I would not want to tear the thing apart. 10 years seems like a long time and it is if you are 20 years old, it is half of your life. It is only one sixth of my life so it doesen't seem very long. :D

[Stuart60611]

For what it is worth, I have never been a fan of deep sandbeds and have zero nitrates (or at most 5), despite extremely heavy feeding and very messy eaters. I have a FOWLR with triggers, a large wrasse, etc. which is fairly heavily stocked and have no clean up crew. My sandbed is about 1 inch to 3/4 of inch deep in the display of arganite gravel. My refugium has no sand whatsoever and is loaded up with rock and topped off with macro chateo algae. I feed massive amounts of food several times per day (large meaty foods which often break apart into many little pieces which get sucked through the system) which mostly gets eaten, but it is not unusual for some significant amount of food to not get eaten when I feed a bit too heavy. I am amazed by the fact that unlike my prior system and without a clean up crew, I have no algae to speak of and near zero nitrates (usually undetectable or at most 5 when my feeding gets a bit out of control), despite my heavy bioload and feeding regime. My system is about 1 year old. My prior system had about a 3-4 inch sandbed and regularly suffered from excessive nitrate and algae problems. I do water changes at most every three months simply to replace trace elements and usually only change about 20% of the water. My skimmer is also not the greatest and is an air driven venturi type which is rated to handle up to (but not exceeding) my system size. By no means anything scientific, but just my personal experience.

[jimbo1]

Interesting thread, I'm running a bb 90g cube.

my nitrates were in the 100ppm mark a few weeks ago.

Plan A
- I started vodka and felt nothing changed, maybe I didn't dose it long enough, the only increase was my cyano.

Plan B
- Changed to wet skimming
- Adding sugar and more frequent water changes . previously my w/c 8% had been every two weeks and I have now increased them to every 3-4 days.

my nitrates are now between 10-25 ppm (salifert kit)

current parameters:
sg=1.026
magnessium=1200
temp=25.5
alk=7
calcium=410

I don't know if the sugar has anything to do with it, but I think the water changes have made a difference.

keep the posts coming guys&gals

[jesterns2]

Ok I have a nitrate of 20ppm and I only have 1.5 to 2inches of sand. I have 2 Ocellarous Clowns. If I need to deepin my sand how do I go about that, put them in a QT?

[Paul B]

I think you should leave your tank just as it is. 20ppm of nitrate in a new tank is actually a little low. Leave it alone and let the bacteria grow. Don't get crazy, have a drink and go watch TV.
The clowns will be fine

[jesterns2]

You say that ina manner that leads me to believe that you may want a particular nitrate level? I thought especially when you go Reef that you don`t want Nitrates? I`m sure once I get a better skimmer next week and get the sump i`m gonna be makin that I should be able to get rid of those nitrates hopefully

[Konadog]

<a href=showthread.php?s=&postid=14597070#post14597070 target=_blank>Originally posted</a> by jesterns2
You say that ina manner that leads me to believe that you may want a particular nitrate level? I thought especially when you go Reef that you don`t want Nitrates? It's more that your sig says "just started" that warrants the comment. If your tank is fairly young, it's not a great idea to go chasing numbers. It takes some time for things to settle in on there own, and if you start changing things before the tank has had a chance, it will take a very long time to start working correctly.

[jesterns2]

Gotcha!

[vermonter310]

<a href=showthread.php?s=&postid=14592829#post14592829 target=_blank>Originally posted</a> by wayne in norway
I don't want to seem a smart arse but this is hardly ground breaking news is it? FWIW I use a medium lengh dsb with a stack of flow over the top and have had zero nitrates for a while now, and it looks pretty stable. The amount of flow in combination with the grain size is the driver on how deep you need to go to get from a (useful) low oxygen zone to an (unhelpful) zero oxygen zone.
I haven't seen numbers on how much ammonium makes it back up thro' the sand bed without being reoxidised. I guess it's presence reduces the need for the bacteria to use/remove nitrogenenous compounds from the water in the 'water' part of the display, and so reduces it's effectiveness as a secondary effect.
FWIW I would think an inch and a half is a bit shallow - if you plough the papers on the subject you'll find there's quite a bit of flow, movement of water and light solids thro' the sand bed at that sort of depth.

Sounds to me like that might be the trick. Getting the depth, grain size and flow to work together to create low oxygen zone while avoiding creating the no Oxygen zones in the deeper sections. or at least creating more of an hypoxic zone and less of a anoxic zone.

While a 3 inch sandbed with a certian size grain may not allow the anoxic zone to develop in a system with good flow, in a system with less flow, it may. Same would apply to grain size and depth, hence the balancing act .

if the same system had larger grain size, even more flow and less depth(or a combination of the three) it most likely wouldn't create the anoxic zone but may not create enough of the hypoxic zone to reduce the nitrates or Ammo created by the bioload of the system. this would explain why some systems seem to work with both approaches..

Of course, I didn't stay at a holiday inn last night so I may be way off base.

[rynon]

I disagree that "no" creature will burrow into hydrogen sulfide. I will guarantee there is a creature that will burrow and thrive in that....finding it will be a different story. There is something for everything when it comes to the ocean, the thing we're trying to replicate.

[MileHighFish]

Well true there are animals/life/organism's that sit at the mouths of thermal vents deep in the ocean, but I dont think they apply here :)

[jenglish]

<a href=showthread.php?s=&postid=14593254#post14593254 target=_blank>Originally posted</a> by Luigi
Just FWIW you are confusing the term anoxia, this means NO OXIGEN. What you mean is HYPOXIA this means low oxigen.

And I have been using DSB 10cm deep for at least 5 years and my nitrates stay near cero. So probably the harmful depth must be deeper...

What you are saying is correct but in the hobby they often switch the terms around. I generally say low oxygen or no oxygen instead of the terms to avoid confusion.

[Mike31154]

Don't think I've ever seen a part of the ocean floor that is BB.

[MileHighFish]

<a href=showthread.php?s=&postid=14606121#post14606121 target=_blank>Originally posted</a> by Mike31154
Don't think I've ever seen a part of the ocean floor that is BB.

Its not, but its not sugar sand either its more like coral rubble.

[jenglish]

<a href=showthread.php?s=&postid=14606121#post14606121 target=_blank>Originally posted</a> by Mike31154
Don't think I've ever seen a part of the ocean floor that is BB.

No part of the ocean is BB but the reeftop biotope that many SPS come from is a long ways from a sandbed too. If you are trying to replicate an huge reef in a small tank (and they are all small tanks :)) then you you may want to just pick part of the tank to replicate.

[Paul B]

I think the ocean has a UG filter, we just haven't seen the uplift tubes yet :D

I disagree that "no" creature will burrow into hydrogen sulfide. I will guarantee there is a creature that will burrow and thrive in that....finding it will be a different story. There is something for everything when it comes to the ocean, the thing we're trying to replicate.

I do a lot of collecting where I lift big flat rocks to get crabs, worms, pods etc. About half the rocks are stuck firm to the mud where no air enters. These have nothing byt hydrogen sulfide under them and nothing else but stink. There is no animals what so ever. Not even a worm. Just of course bacteria. And if you leave that rock up side down, those bacteria die shortly and the rock eventually becomes live rock as I have a bunch of them in my tank. Any animal that you find living in Hydrogen sulfide will have a hard time living in an oxygen envirnment.

[TulsaReefer]

<a href=showthread.php?s=&postid=14576723#post14576723 target=_blank>Originally posted</a> by Paul B
Dave, I guess the theory doesen't work on every tank, what can I say? Also your DSB is very young.

Ken I feel all DSBs will crash in a number of years. Eventually the small spaces between the sand have to become completely clogged and being you can't maintain them I do not see any other result. I think ten years (which is just a guess) should do it.
(of course I could be wrong, me not being the God of DSBs)
I do not think any critters will burrow into a non oxygenated area that most likely has hydrogen sulfide.

Phil, according to the research as long as the grains are larger and some oxygen gets through you will have more anoxic zones than anerobic zones and it should be fine.

I am curious, how many people here have a DSB for five or ten years or longer? We will never know the answers to these questions unless we have an accurate count. And out of those beds, how many (if any) read anynitrates?

I had a sand bed in a tank for right at 10 years before I finally tore it down last fall to upgrade to a larger tank. Though I'm not sure it qualified as a "DSB" since it seems to be a rather broad term. It contained anywhere from 1" to 3" (maybe almost 4" in some areas) of sugar fine oolitic sand. When I tore the tank down the sand had no areas of hydrogen sulfide as it's quite easy to detect when digging sand out of the bottom of a tank. I found burrowing worms down to the lowest level actually burrowing right at the bottom glass and sand interface in even the deepest areas.

If your trying to use this article as a treatise on why sand beds are bad, then your only really proving that sand beds that are too deep, i.e. improperly created and maintained sand beds are bad. So what's the news there, almost anything improperly done in this hobby can be a problem. I'm not sure how many people went out and tried to build sand beds that contained a large portions of anoxic areas that this article is focused on. We already knew that Nitrate reduction was done in hypoxic zones, not anoxic and that there was always a danger of H2S formation in anoxic areas with organic matter present. With this knowledge I wouldn't throw out the idea of using a sand bed, I'd try to work around that to minimize those risks. If my sand bed is too shallow it may not reduce Nitrate, but then it's also not harming anything either, and Nitrate reduction isn't the only reason to have sand in my view. So I tend to error on the shallow side, and use additional measure to help in Nitrate control (good skimming, water changes, growing nitrate consumers such as algaes, etc.).

I find the additional diversity I get with a sand bed worthwhile, as well as I enjoy the look of it as well. My new tank has again anywhere from maybe 1 1/2" to 3 1/2 inches of sugar fine oolite , much of it harvested from the old tank. I have a huge population of burrowing pods (they look like tiny mantis shrimp, but never get bigger than about 1/4 inch) that burrow all over the sand, and where the burrows show along the edges of the glass, they burrow down at least an inch or two, showing that there must be decent oxygen levels there, or as you had said they wouldn't go there. And if I scoop up a cup of sand and look through it, I have a great population of worms and other tiny creatures that inhabit the sand. My Mandarin spends a good part of the day hunting in the sand bed, picking small creature out, and it's quite large and healthy. I think that diversity is good, and without the sand a huge part of that would be gone.

[ctenophors rule]

so, if the life rock is bad when it is large because it does not have enough oxygen, could it be possible that;

making live rock, and placing clumps of salt in the middle, that will be washed out later could prevent all of this by allowing more aireated water flow?

making live rock hollowish, so their are only ever 3-4 inches of live rock, before water is flowing thour the other side?


thanks, interested in knowing

[TulsaReefer]

<a href=showthread.php?s=&postid=14606822#post14606822 target=_blank>Originally posted</a> by MileHighFish
Its not, but its not sugar sand either its more like coral rubble.

You really have to qualify that type of statement, as it depends on location. The ocean is a large place, and every reef is a little different. I've seen reefs with mainly rubble zones (typically higher energy reefs), and some less energetic (usually on the back sides of barrier reef, and more lagoon type) have very fine silty sand. So it's a bit difficult to argue that "reef" do or don't have any particular botton structure.

In the USVI I watched armies of parrot fish "make sand" in what seemed to be good quantity as they chewed off bits of the reef and excreted it back out as fine sand (I don't think they can pass rubble :), or at least it would be a bit of a strain).

[ctenophors rule]

the way i see it is that most of the ocean has incredibly small particled sand, and this is primarily located in the depper more oxygen deprived parts of the ocean, but their are other forces at work. depper where this bacteria should be more common, their may be a heterotrophic archeabacteria that eats them, and controls their population, or their may be a bacteria deeper in the sand that absorbs every thing the bad bacteria made,

their are bacteria in 50 feet deep sugar grain sand, their is bacteria fozen in the poles that still survives. their is bacteria everywhere in short.

their are millions, if not billions of different species of bacteriums that we may never find, recently a study was done in a lake and 100+ new species were found in single sample.

we just need to know m,ore about the ecology of this bacteria, and its natural wild husbandry.

[superedge88]

I can't help but chuckle, are we really trying to equate our aquariums to the ocean? Trying to dissect what kind of sandbeds are in the ocean as if that is what we should mimmic because then our aquariums would "work" right. The ocean has millions of other factors (the largest one being dillution of most of the things we are trying to avoid like nitrate) and to back that up the ocean has some of the most thriving examples of photosynthetic organisms in the world to act as a back up for consuming nitrate/phosphate etc. So to start a conversation about "the ocean isn't bare bottom so our tanks shouldn't be" or "I use coral rubble because that is what the ocean has" from the standpoint of water quality, it is pretty pointless.

[Aquarist007]

I understand that there are three types of bacteria in the nitrogen cycle. and I understand that anoxic bacteria are key to reducing nitrates to nitrogen gas--completing the cycle.
I further understand that the anoxic bacteria thrive in areas of very low oxygen.
What I don't understand then is why a deep sand bed is NOT suitable for maintaining them as is the deep core of live rock.

[Qcks]

Personally... i think the article was good because it pointed out a mechanism for direct atmospheric nitrogen fixation by a bacterial community.
The ability to directly fix atmospheric nitrogen isn't well understood. If it was, farmers wouldn't need to spend millions on fertilizers each year.
I liked that the article mentioned that ammonium was more readily usable then nitrate (ammonium was energetically favorable to nitrate, meaning it's more easily used then nitrate.). That means that ammonium doesn't necessarily go through the entire nitrogen cycle. It skips directly to the convertion back into atmospheric nitrogen. It does however mean that it blocks the uptake of existing nitrates.

The article does hint at why some deep sand beds may become nitrate producers over time though.

If you look, you'll note that the article says that most denitrifiying bacteria are primary consumers of mono and Di-saccrides.

Mono and Di-saccrides are things like Glucose and ethanol.

I believe that the reason why Deep Sandbeds stop denitrifying over time is because the denitrifying bacteria that live in the sandbed deplete these particular nutrients. That's why if you leave a Remote Deep Sandbed to stagnate, it can eventually be hooked backup and consumes nitrates again. The die off of the aerobic organism in the top layer of the sandbed replenishes the Dissolved Organic Carbon.
This also largely accounts for why carbon dosing works.

[Paul B]

I had a sand bed in a tank for right at 10 years before I finally tore it down last fall to upgrade to a larger tank. Though I'm not sure it qualified as a "DSB" since it seems to be a rather broad term. It contained anywhere from 1" to 3"

Tulsa, conisidentially, the author said to me that 1' to 3" for a DSB is perfect. That is not really the depth of a DSB he is talking about.
I think more like 4" and deeper, acording to the author "may" be a problem.
He also did not say that this will always happen in a deeper bed, although I don't know why.

As for live rock, I happen to disagree with him on that point and feel you can't have too much live rock. I don't think rock and deep sand would qualify as the same thing. But much of my rock is hollow because I built it like that. Not for nitrate reduction which I diden't think about at the time, but just because it is easier tio build like that.

Capn, Bob seems to think from his research or more likely, the research of the people he quotes that this problem with the anerobic bacteria in deeper areas where there is almost no oxygen at all harbors bacteria slightly different from the anerobic bacteria we have always known about that just turn nitrate into nitrogen gas which disapates out of the water. This other bacteria convert the nitrogen gas back again into ammonium which the shallower bacteria again convert back into nitrates.

I am only posting the article I did not write it but I feel that too many DSBs have nitrogen problems where there should be none.
This sounds like a plausable theory to me other wise, where is the nitrate coming from in a tank with a DSB?
Again, if a DSB is not working and we have a nitrogen problem, what exactly is the DSB doing?
There should be way more nitrates in my tank than a tank with a DSB and that is not always the case. Maybe this theory
(which I did not write) is true.
:smokin:

[TulsaReefer]

I try to keep an open mind, as well as will give credit where it's due, and Bob Goemans deserves a lot of credit for his contributions to this hobby. But he lost me as a reader of his work back in 2003 after he wrote a glowing product review that tried to "explain the science" behind the infamous snake oil product, the "Eco Aqualizer". After that, when Bob writes a "theory" it's a bit hard for me to take it for face value. Now does this mean he's wrong this time, no it doesn't prove that, but what it does mean for me is I'll wait until I see someone else publish a paper that supports his theory, as I don't really have the time or education to dig into this myself. And I don't find Bob a source I'm willing to trust on face value.

[Paul B]

Tulsa, I also do not agree with Bob on everything and I don't even know what an Eco Aqualizer is.
I know Bob and he has been to my home even though he lives in Arizona and I am in NY.
I do know that he has been in the hobby a little longer than me and he is the only person I know that has.
Along the way he has had to have learned at least a little more than many people on here. I myself have written things in articles years ago that I don't agree with anymore.
You have to take every article you read with a grain of salt and try to figure out from your own experiences if it seems plausable.
The problem with these theories and this hobby in general is that are more variables than there are people.
I run a RUGF. Would you try to get someone to do that?

[TulsaReefer]

Agreed. I guess my perspective is this, I am not a scientist, I'm an engineer. If I write something outside my profession and education it's as a hobbyist. From my perspective, Bob is the same since he isn't a scientist either, so he falls in the same class as myself, a hobbyist, though with long set of experiences. What I'm saying is that while he may be absolutely correct, I look forward to someone who is a scientist, who can properly work through the science involved, and can then properly take that theory and have it peer reviewed, or at least published in a journal that does review before I take too much stock in it. And I hope someone will take up Bob's theory and work it through a more formal process. It would be interesting to see another view on this topic other than a hobbyist viewpoint.

[luther1200]

<a href=showthread.php?s=&postid=14608983#post14608983 target=_blank>Originally posted</a> by superedge88
I can't help but chuckle, are we really trying to equate our aquariums to the ocean? Trying to dissect what kind of sandbeds are in the ocean as if that is what we should mimmic because then our aquariums would "work" right. The ocean has millions of other factors (the largest one being dillution of most of the things we are trying to avoid like nitrate) and to back that up the ocean has some of the most thriving examples of photosynthetic organisms in the world to act as a back up for consuming nitrate/phosphate etc. So to start a conversation about "the ocean isn't bare bottom so our tanks shouldn't be" or "I use coral rubble because that is what the ocean has" from the standpoint of water quality, it is pretty pointless.


THANK YOU, I was glad somebody said it before I got to the end.

[luther1200]

Just to start I am not a DSB fan either. But I would think a finer sand would be better. A larger grain would allow more setritus to build up and cause the DSB to "foul" faster IMO. So maybe a larger grain would work better at first, but unless you did frequent WC to clean it with gravel vac you would get more build up, IMO. With a finer sand it can be more easily circulated into the system with water movement, As it will sit on the top of the sand longer.

On another note I think most people have nitrate problems because of overstocking, and over feeding. There is only so much the bacteria on LR and LS can do in a finite area. That is why I believe RDSB work for some people.

[Aquarist007]

<a href=showthread.php?s=&postid=14609899#post14609899 target=_blank>Originally posted</a> by Paul B


Capn, Bob seems to think from his research or more likely, the research of the people he quotes that this problem with the anerobic bacteria in deeper areas where there is almost no oxygen at all harbors bacteria slightly different from the anerobic bacteria we have always known about that just turn nitrate into nitrogen gas which disapates out of the water. This other bacteria convert the nitrogen gas back again into ammonium which the shallower bacteria again convert back into nitrates.



anerobic bacteria in deep areas where there is no oygen--to my limited understanding this is a false statement in that one part negates the other. Anerobic bacteria can't live in areas devoid of oxygen--only anoxic bacteria which breat down the nitrates to nitrogen gas????

[Aquarist007]

We need somebody like Greenbean or Randy to jump in here :)

[tmz]

The sand bed debate will go on and on and on.There are thousands of pages on it.
Personally, I've tried a number of variations. I have observed many tanks with deep sand beds 4 plus inches with healthy bioloads and near 0 nitrates. I removed a deep sand bed from part of my system and observed a rise in nitrates. Tried remote unlit sand beds too and find them particularly useless,in my experience. Others have noted success with them.

I prefer a shallow bed from a maintenance and aesthetic( I like a beachy look)perspective unless I'm keeping creatures that need more sand, such as certain fish, anemones and corals like sea pens.. All the variations should work with proper care and attention.

If you keep a large fish population and feed them well, you will likely at some point have an issue with nitrate and phosphate, no matter which way you go with your substrate choice. It's just how it is. Refugia with macro algae can help. A sulfur denitrator will do wonders for nitrate. Gfo can control phosphate.Ozone ,carbon,aggressive skimming ,live rock and yes even water changes can help you get it under control and keep it there.

Somewhere,in the explanation of ammonium production a claim to a new theory has risen. It just ain't so and it ain't new , in my opinion. In fact the recommendation for a plenum in the article is really old school.

I believe their are some inaccuracies stated above as well. For example: as far as I know, the only organisms to fix free nitrogen gas are cyanobacteria and their cousins like chloroplasts. All of these photosynthetic organisms rely on anoxic sacs(heterocycts) within their structures to produce and use a unique substance(nitrogenase) which enables the fixing of free nitrogen back into organic forms. I do not believe the creation of ammonium from nitrate and hydrogen has anything to do with this and can't imagine photosynthesis occurring in the dark depths of a sandbed.

In my opinion, folks should plan an aquairum based on what they wan't to keep in it . Substrate, should follow the same path. Deep, bare, etc; less or more live rock, can all work in sync with the rest of the system and system supports if you are keeping larger bioloads (such as gfo, carbon, nitrate reactors and so on).Frequent measurements of critical parameters including phoshate and nitrate will tell you when you have to make a change and there are many options to choose from when you do.

[Gravesj1s]

Hmmmm, I dont think NO3- is so much as an issue as PO4 has a real potential to become a problem .
The Goemans article is misleading and flawed.
-Graves

[tmz]

<a href=showthread.php?s=&postid=14613292#post14613292 target=_blank>Originally posted</a> by Gravesj1s
Hmmmm, I dont think NO3- is so much as an issue as PO4 has a real potential to become a problem .
The Goemans article is misleading and flawed.
-Graves :)High phosphate will interfere with calcium carbonate precipitation. This impairs the coral's ability to calcify and throws it out of balance. High phosphate can quickly harm corals, particularly sps. It will also fuel nuisance algae.It is a limiting factor for green algaes including nuisance algaes such as derbasia and bryopsis. So keeping it very low ( under 0.1 ppm) will limit their growth.

Nitrate can be a problem at higher levels ( above 30ppm in my experience) . It drives zooxanthelae growth which can also be harmful to corals . Some types more than others. I have noticed in my experience that montipora, seriatopora and stylopora do poorly in high nitrates and quite well in near 0 nitrate water. Leather corals seem to like the extra nitrogen source. It will also fuel nuisance algae growth

[Joe Pusdesris]

The idea of nitrogen fixation occurring deep in a sandbed is quite interesting. I had thought the majority of fixation in the reef took took place because of cyanobacteria, but this makes sense. Fixation takes place in soil, so why not sand. Fixating diatomic nitrogen takes a lot of energy. In an area devoid of light, the bacteria would need an alternate energy source to fixate nitrogen, say organic carbon. This may be why VSV with deep sand beds prove to be problematic.

Algae and fishfoods also contain energy in the form of organic carbon. Given the information provided earlier in the thread, it would seem important to ensure there are enough organisms to use up the majority of energy in these foods rather than letting it feed bacteria in the sand bed. This may be why sand beds with a lot of worms tend to yield better results than those without.

I myself, am a fan of sandbeds. Only because sand is so much cheaper than rock and serves a similar role in the aquarium.

[tmz]

I think the bacteria in a deep sand bed devoid of oxygen would turn to sulfate creating hydrogen sulfide as the concern with carbon dosing and dsbs.

[Joe Pusdesris]

<a href=showthread.php?s=&postid=14616267#post14616267 target=_blank>Originally posted</a> by tmz
I think the bacteria in a deep sand bed devoid of oxygen would turn to sulfate creating hydrogen sulfide as the concern with carbon dosing and dsbs.

Yes, providing they were oxygen limited rather than nitrogen limited.

[Aquarist007]

<a href=showthread.php?s=&postid=14616267#post14616267 target=_blank>Originally posted</a> by tmz
I think the bacteria in a deep sand bed devoid of oxygen would turn to sulfate creating hydrogen sulfide as the concern with carbon dosing and dsbs.

I thought this condition(deep sand bed devoid of oxygen) supported the growth of anoxic bacteria--the nitrate reducers?

[Joe Pusdesris]

<a href=showthread.php?s=&postid=14616649#post14616649 target=_blank>Originally posted</a> by capn_hylinur
I thought this condition(deep sand bed devoid of oxygen) supported the growth of anoxic bacteria--the nitrate reducers?

When they run out of oxygen, they strip the oxygen off of nitrate (NO3). When they run out of nitrate, they strip the oxygen from suflate (SO4), then carbon dioxide (CO2).

[Gravesj1s]

<a href=showthread.php?s=&postid=14614296#post14614296 target=_blank>Originally posted</a> by tmz
:)High phosphate will interfere with calcium carbonate precipitation. This impairs the coral's ability to calcify and throws it out of balance. High phosphate can quickly harm corals, particularly sps. It will also fuel nuisance algae.It is a limiting factor for green algaes including nuisance algaes such as derbasia and bryopsis. So keeping it very low ( under 0.1 ppm) will limit their growth.

Nitrate can be a problem at higher levels ( above 30ppm in my experience) . It drives zooxanthelae growth which can also be harmful to corals . Some types more than others. I have noticed in my experience that montipora, seriatopora and stylopora do poorly in high nitrates and quite well in near 0 nitrate water. Leather corals seem to like the extra nitrogen source. It will also fuel nuisance algae growth

tmz hi , I think maybe I was a bit vague in my post you qouted. I meant PO4 is more of an issue than No3 in deep sand beds.
I still think the Goemans article is misleading....give it a few months and he will be promoting a product to reduce Ammonium.
-Graves

[Aquarist007]

<a href=showthread.php?s=&postid=14616802#post14616802 target=_blank>Originally posted</a> by Joe Pusdesris
When they run out of oxygen, they strip the oxygen off of nitrate (NO3). When they run out of nitrate, they strip the oxygen from suflate (SO4), then carbon dioxide (CO2).

tell us more Joe--you seem to be in the know here:smokin:

this is good isn't it?
if they strip the oxygen away from the nitrates---isn't that their purpose--thus reducing nitrates to nitrogen gas??

[jenglish]

If these nitrogen fixing bacteria are present in no oxygen zones, it is still not creating any more nitrogen in the system than if the sand was not in the system. The DSB would not be bringing more nitrogen into the system, but this could explain some of the nitrogen cycling back into the system, but only some IMO

[Joe Pusdesris]

<a href=showthread.php?s=&postid=14617500#post14617500 target=_blank>Originally posted</a> by capn_hylinur
tell us more Joe--you seem to be in the know here:smokin:

this is good isn't it?
if they strip the oxygen away from the nitrates---isn't that their purpose--thus reducing nitrates to nitrogen gas??

Yes, that's the idea. The statement made to start this thread though is that in the depths of a sandbed without oxygen an enzyme like Nitrogenase can be sustained. (Oxygen breaks down the enzyme) Such enzymes are catalysts in the process of converting nitrogen gas to ammonia.


If these nitrogen fixing bacteria are present in no oxygen zones, it is still not creating any more nitrogen in the system than if the sand was not in the system. The DSB would not be bringing more nitrogen into the system, but this could explain some of the nitrogen cycling back into the system, but only some IMO

Valid point. The thing you are missing is that nitrogen gas is soluble in seawater. In fact, it is more soluble than oxygen, and there is almost nothing that uses it up (Except nitrogen fixators like cyanobactera and bacteria being discussed now), where almost everything in the system uses oxygen. Considering how much oxygen can reach the sandbed, you can deduce that much more nitrogen gas can make it's way down there. So it is possible that nitrogen gas which dissolved in the water from the atmosphere makes it down into the sand bed, thus increasing net nitrogen.

[tmz]

Where would the nitrogenase come from? I thought it was uniquely produced by cyanobacteria ?

[Joe Pusdesris]

<a href=showthread.php?s=&postid=14618505#post14618505 target=_blank>Originally posted</a> by tmz
Where would the nitrogenase come from? I thought it was uniquely produced by cyanobacteria ?


I do not know much about biology but some googling shows that Azotobacter is a bacteria that lives in aerobic conditions and can fix nitrogen in soil. I do not know if this bacteria can survive in marine conditions or if it is the same bacteria genus as is what was discussed in this thread. But it is a non-cyano example nonetheless.

[Aquarist007]

<a href=showthread.php?s=&postid=14617887#post14617887 target=_blank>Originally posted</a> by Joe Pusdesris
[B
Valid point. The thing you are missing is that nitrogen gas is soluble in seawater. In fact, it is more soluble than oxygen, and there is almost nothing that uses it up (Except nitrogen fixators like cyanobactera and bacteria being discussed now), where almost everything in the system uses oxygen. Considering how much oxygen can reach the sandbed, you can deduce that much more nitrogen gas can make it's way down there. So it is possible that nitrogen gas which dissolved in the water from the atmosphere makes it down into the sand bed, thus increasing net nitrogen. [/B]

I thought that oxygen, nitrogen and carbon dioxide gases, being lighter then seawater would rise to the surface and bubble off---not be a contributing factor on the surface of the dsb and definetly not a factor in the deep zones which support anoxic bacteria.?

[jenglish]

<a href=showthread.php?s=&postid=14617887#post14617887 target=_blank>Originally posted</a> by Joe Pusdesris


Valid point. The thing you are missing is that nitrogen gas is soluble in seawater. In fact, it is more soluble than oxygen, and there is almost nothing that uses it up (Except nitrogen fixators like cyanobactera and bacteria being discussed now), where almost everything in the system uses oxygen. Considering how much oxygen can reach the sandbed, you can deduce that much more nitrogen gas can make it's way down there. So it is possible that nitrogen gas which dissolved in the water from the atmosphere makes it down into the sand bed, thus increasing net nitrogen.

I can see this being theoretically a net gain in nitrogen, but in practical terms I don't see this happening short of having pure nitrogen gas above your aquarium. In a practical example you would have to have sufficient nitrogen fixing bacteria in the substrate to process nitrogen into ammonium. To get a net addition of nitrogen to the tank you would need these in sufficient quantitiy to process all the nitrogen put into the tank plus more dissolving. This seems unlikely to me. I can't rule this out but it seems doubtful. This would be a testable hypothesis though if someone had a established DSB and removed all critters and quit feeding it. If the nitrate levels kept rising, then this could be confirmed no?

[jenglish]

<a href=showthread.php?s=&postid=14618653#post14618653 target=_blank>Originally posted</a> by capn_hylinur
I thought that oxygen, nitrogen and carbon dioxide gases, being lighter then seawater would rise to the surface and bubble off---not be a contributing factor on the surface of the dsb and definetly not a factor in the deep zones which support anoxic bacteria.?

depends on the gas content in the air. If gasses always rose and bubbled off then CO2 in your home rising would not effect ph in the winter. I have watched gasses rise to the surface so I understand what you are saying but gases are dissolved as well

[Joe Pusdesris]

Oops, my mistake. Sorry everyone, the Azotobacter I found earlier lives in aerobic conditions, but there is a whole list of other bacteria that live in anaerobic conditions below, it would seem they are more productive as well.
http://en.wikipedia.org/wiki/Diazotroph

jenglish, the gas above your tank is N2. Well, mostly. Air is almost 80% nitrogen. Fun fact, that nasty CO2 in our houses that effects ph so much is only about .04% of air.

Also, those that doubt air dissolves in water, either do some reading or shake a bottle of pop, whatever you prefer. :)

[tmz]

<a href=showthread.php?s=&postid=14618589#post14618589 target=_blank>Originally posted</a> by Joe Pusdesris
I do not know much about biology but some googling shows that Azotobacter is a bacteria that lives in aerobic conditions and can fix nitrogen in soil. I do not know if this bacteria can survive in marine conditions or if it is the same bacteria genus as is what was discussed in this thread. But it is a non-cyano example nonetheless. :) Thanks for the reply. Yes a non cyano example; so are chloroplasts , but azobacter sounds a lot like cyano and may have evovled from it in that it too forms anoxic cysts where athmospheric oxygen is fixed but the actual azobacter organism is aerobic so it's existence in the soil doesn't support the notion that bacteria which thrive in anoxic zones would be able to fix nitrogen.

[jenglish]

<a href=showthread.php?s=&postid=14618771#post14618771 target=_blank>Originally posted</a> by Joe Pusdesris
Oops, my mistake. Sorry everyone, the Azotobacter I found earlier lives in aerobic conditions, but there is a whole list of other bacteria that live in anaerobic conditions below, it would seem they are more productive as well.
http://en.wikipedia.org/wiki/Diazotroph

jenglish, the gas above your tank is N2. Well, mostly. Air is almost 80% nitrogen. Fun fact, that nasty CO2 in our houses that effects ph so much is only about .04% of air.

Also, those that doubt air dissolves in water, either do some reading or shake a bottle of pop, whatever you prefer. :)

Yes, air is at nearly 80% nitrogen but it has been shown that low oxygen bacteria can turn NO3 to nitrogen gas and gas it off into this 80%. This is how coil denitrators, DSB and large LR all work So for this absorbtion of additional nitrogen gas would to me be unlikely under normal enviromental conditions.

Shaking a pop would be more of an example of off gassing than natural absorbtion of atmospheric gasses.

[tmz]

Sorry , I missed your follow up post.

Thanks for the link on diazotrophs and the knowlegeable discussion.

I noted that the diazotrophs are primarily involved in symbiotic realtionships with root structures or intenstines etc.Couldn't find any listed that weren't.

Nonetheless, I guess it's possible to specualte that some non symbiotic form of nitrogen fixing anerobe(probably evolved from cyanobacteria lol) could exist in a deep substrate but none have been so identified to my knowledge. Maybe a biologist or two could chime in.

Even if non symbiotic diazotrophs did exist deep in the sand bed ,fixing athmospheric nitrogen would it seems be a challenge for them in terms of energy as you noted earlier. It also seems the alack of a carbon source would make this less likely. If decaying matter found it's way down there as the carbon source, I think it is likely that the nitrate and some oxygen might as well making it very unlikely that a net gain in organicaly bound nitrogen would result.

BTW do you happen to know if nitrogen is more or less likely to diffuse into a deep bed than oxygen or nitrate ? I don't know that but would like to..

While this speculation is very interesting I don't think it's a "new nitrate theory" and isn't a reason to ban deep sand beds as a vialbe option for denitrification in favor of plenum designs or other approaches. I still think hyrdrogen sulfide formation particulary with carbon dosing is a potential threat to the aquarium with a deep sand bed, however.

[Joe Pusdesris]

N2 dissolves in seawater to a level around 20 mg/L. Quite high indeed. And with a protein skimmer or good gas exchange, I would imagine any nitrogen lost is replaced quite quickly.

Source: http://www.lenntech.com/elements-and-water/nitrogen-and-water.htm



While this speculation is very interesting I don't think it's a "new nitrate theory" and isn't a reason to ban deep sand beds as a vialbe option for denitrification in favor of plenum designs or other approaches. I still think hyrdrogen sulfide formation particulary with carbon dosing is a potential threat to the aquarium with a deep sand bed, however.

Indeed. I have just seen far too many miserable looking tanks with shallow sand, and I haven't seen too many deep sand bed tanks that look terrible. Maybe it is because people new to the hobby tend to go with shallow sandbed, I don't know. I hope people do not start posting how their shallow sand bed looks 'fantastic.' I am judging by the % of failure, not isolated successes.

The only true problem I find with sandbeds is that they blow around. Corals do not like being covered in sand, and I like to have a lot of flow. Tanks with barebottom displays and deep sand bed refugiums seem to have the best of both worlds to me. I am not going to dig out my sandbeds any time soon.

[Aquarist007]

<a href=showthread.php?s=&postid=14620034#post14620034 target=_blank>Originally posted</a> by Joe Pusdesris
N2 dissolves in seawater to a level around 20 mg/L. Quite high indeed. And with a protein skimmer or good gas exchange, I would imagine any nitrogen lost is replaced quite quickly.

Source: http://www.lenntech.com/elements-and-water/nitrogen-and-water.htm





Indeed. I have just seen far too many miserable looking tanks with shallow sand, and I haven't seen too many deep sand bed tanks that look terrible. Maybe it is because people new to the hobby tend to go with shallow sandbed, I don't know. I hope people do not start posting how their shallow sand bed looks 'fantastic.' I am judging by the % of failure, not isolated successes.

The only true problem I find with sandbeds is that they blow around. Corals do not like being covered in sand, and I like to have a lot of flow. Tanks with barebottom displays and deep sand bed refugiums seem to have the best of both worlds to me. I am not going to dig out my sandbeds any time soon.

Thank you for validating that----remote dsb's as in a refugium are the way to go. Most of my experience has been gained through participation on this site and I have found that reefers who are much more experinced in reef keeping then me seem to be opting for that setup.
IMO its easy to question the functionality of deep sand beds in our tanks when one can easily load up the biomass in their tanks, over feed that biomass and not supply enough quality live rock and macroalgae---all variables that even the best of deep sand bed setups could not reduce the amount of nitrates significantly.

[Paul B]

While this speculation is very interesting I don't think it's a "new nitrate theory" and isn't a reason to ban deep sand beds as a vialbe option for denitrification in favor of plenum designs or other approaches.

I would not Ban DSBs, only the ones which don't seem to be working.

[Gravesj1s]

Guys , I got to admit Iam somewhat confused here. I read a study that suggests a little over an inch of substrate is where nitrification and denitrification is most likely occuring.If memory serves me right most was occuring in the first couple of milimeters.(70%) the remainder 30% was found within a centimeter.

I guess I dont see the point otherwise unless someone has actual evidence that a dsb in a remote bucket,fuge or intank has more benefits that Iam unaware of ,please enlighten me.
-Graves

[Paul B]

I guess I dont see the point otherwise unless someone has actual evidence that a dsb in a remote bucket,fuge or intank has more benefits that Iam unaware of ,please enlighten me.

Yeah, enlighten me also :D

[jenglish]

I think the problem with "proving" is we would need to isolate a single independant variable, sand depth, with sufficient N for statistical significance and run multiple tanks long term. So lets wait until muy fiancee becomes my ex wife and then maybe I can do a project like that :lol:

[onetrickpony]

http://www.advancedaquarist.com/2005/6/aafeature
http://www.advancedaquarist.com/2005/7/aafeature

[Paul B]

Onetrickpony, thank you for posting those sites.
I read them and also remember when those tests were performed.
I have been around to see the beginning of Berlin systems and jaubert systems.
The article you posted was interesting but was more a comparism of plenum and no plenum systems. They said there was no significant difference and I think the same thing.
Unfortunately where it comes to these laboratory tests, they were performed for (I think) 114 days which is a very new system and doesen't mean much in a tank where we want stability for years not days.
All systems will change over time. The substrates used in the tests were taken from Hawaiian waters which would differ significantly from a hobbiests tank who most likely uses ASW and does not add bacteria or nutrients from the sea. (besides me)
Also the bacterial diversity in an aquarium is severly limited compared to fresh sand from the sea.
I would like to see a test over a couple of years with ASW.
as was said in the article
Quote,
"there is far too much variability (Fig. 2) to draw any conclusions based on a single tank. We reiterate the point made by many authors before us: we need experimental rather than anecdotal evidence to draw any conclusions about the relative advantages of any particular aquarium design or additive."

This is true but it is also true that a couple of months does not prove much.
"

[Gravesj1s]

-Paul ,I agree on the comparisons

Her is a comparison for someone with an ongoing algae out break that appaers to have the Goemans symptoms.
The usual poster will run through the testing parameters to find they all check out fine but cant explain the ongoing algae problem.
Stir up some of your substrate and test imediately afterwards for PO4 and NO3.
-Graves

[onetrickpony]

Paul
I would have to agree with you about time and different methods, those like you who have stayed with the hobby for many years, who have seen ideas, methods, equipment all change and stay the same. What was the new hot trend in reef keeping a couple of years ago, 5 years ago, and what will it are a few years from now. I will bet it will come down to marketing.

With everything in this hobby finding what works and what does not work will depend on who you ask. Look at the gap in knowledge between LFS and information on RC

The great thing about Reef Central and other web boards all over WWW is that there is spontaneous gathering of know age, disagreement, and questions always being asked by someone, which leads to other questions, agreements and disagreements.
The flip side to the 2 year thing is this, how many people start and leave the hobby in a 24 month period, 50% – 80%

[Aquarist007]

<a href=showthread.php?s=&postid=14624928#post14624928 target=_blank>Originally posted</a> by onetrickpony
Paul


The great thing about Reef Central and other web boards all over WWW is that there is spontaneous gathering of know age, disagreement, and questions always being asked by someone, which leads to other questions, agreements and disagreements.
The flip side to the 2 year thing is this, how many people start and leave the hobby in a 24 month period, 50% – 80%

I'm amazed at the number of new members we get each day. As we know this hobby is expensive and in this economy it makes one wonder where all the money is coming from.
Maybe its the guys that got the bonus checks from AIB:D

[Paul B]

Capn, I think you are correct, it's the guys that got the bonus checks.
I am submitting this picture of my gobi to the government. I may have to sell his bottle home to make ends meet causing him to be homeless. Poor little guy.
http://i258.photobucket.com/albums/hh270/urchsearch/Gobieggs014.jpg

[Gravesj1s]

During the experiment, the maximum air temperature recorded was 33ºC (~91ºF) and the minimum air temperature recorded was 19ºC (~66ºF); aquarium temperatures varied less than these extremes, and ranged from 22 and 30ºC (~72 to 86ºF).

I took this from the Hovanec article. I was wondering if their were any thoughts on this as far as the temperature swings go. According to some of the works of John wiley & sons-microbes can be sensitive to swings in temperature. I wondered if it would have an effect in this case?
Any thoughts?
-Graves

[dtaylor123]

<a href=showthread.php?s=&postid=14569176#post14569176 target=_blank>Originally posted</a> by Paul B
But I do have an old tank with no DSB with almost no nitrates where I hardly ever have to change water and I never change it because of nitrates.

This is a good subject. Worth investigating. How long has your tank been up and running without a DSB? Is everything happy and your tank thriving? Can you show us with pictures your tank?

There are a lot of theory's and all are interesting. There is also a lot of ways to run a reef tank and many people are successful, even if they go against the latest trend. To me, I like to see results and pictures, again many ways to have good husbandry skills. To me, if your tank is thriving and doing well, then what ever you are doing works.

Good thread and topic. I think challenging against the the "normal" is good and we all can learn. This is why these boards benefit all of us and I truly believe we can learn from each other.

Dan

[Paul B]

My tank has been up and running without a DSB for 39 years.http://reefcentral.com/gallery/data/500/13094Feb_10-5.JPG

[Aquarist007]

<a href=showthread.php?s=&postid=14664266#post14664266 target=_blank>Originally posted</a> by Paul B
My tank has been up and running without a DSB for 39 years.http://reefcentral.com/gallery/data/500/13094Feb_10-5.JPG

forgive me if you have mentioned this before--but how have you maintained your substrate over the years---do you change it out every couple of years?

[Paul B]

I think challenging against the the "normal" is good and we all can learn.

Taylor, the "norm" that people always talk about came about from the internet. Saltwater tanks have been around way before the net when the "norm" was anything we tried that worked.
Now there are three or four people that write books that we casually refer to as "experts" They no doubt are not stupid and have their ways to do things which are, of course, fine. But most of them have the same or similar ways to do things.
With so few knowledgable people writing books the information stagnates a little. There is very little experimentation going on with reefers because instead of learning through trial and error we tend to read what the expert does.
It's like college (sorry Capn) I feel college removes too much of our creativity and we tend to think like the teachers who, unfortunately, have learned from the pool of teachers who all learned from the same book.
I am by far, no expert but I learned everything I know by a lot of failures. I have ways to do things that I don't put on these forums because when I mention something, I get all sorts of negative comments, usually from people with very little experience.
:(
I use things like Clorox, quinicrine hydrocloride, Chloremphenicol and neomyacin, hydrogen peroxide New York mud UG filters, algae trays and Sakrete. I mentioned once how to cure Pop Eye in a few seconds and I got a bunch of E Mails saying I should not mention that because people may kill their fish.
Someone mailed me once saying he killed his fish because I said to put Clorox in his tank. This guy actually put Clorox in his tank and was surprised that the fish died.
:eek1:

Capn, I have never changed my dolomite gravel and it has been in there since the tank was brackish in the late sixtees. It was cleaned in 71 or so but since then, except for occasional diatoming, I have done nothing to it.:smokin:

Capn, if you look closely at that picture above of that fish in a bottle you can see all sorts of things in my gravel. Sea urchin spines, asphalt shells and probably fish bones, it's all in there

[moumda]

Well said Paul.

[Aquarist007]

<a href=showthread.php?s=&postid=14665501#post14665501 target=_blank>Originally posted</a> by Paul B

It's like college (sorry Capn) I feel college removes too much of our creativity and we tend to think like the teachers who, unfortunately, have learned from the pool of teachers who all learned from the same book.


You don't have do apologize to me Paul

I received my auto mechanics experience from a french canadian mechanic who would have me listen to an engine and be able to tell when the bearings were worn on the crankshaft, how to tell the difference between 9/16 and 5/8 bolt by reaching up under the car and feeling it with my fingers ect ect. I changed a motor in my future mother in laws car on the drive way just to impress here a little. It did
After 5 years of this training I went to the first class in automotive enginering at university--when I picked up a wrench they told me I wasn't allowed until second year--I never went back.
Never read a book on automechanics--unless it was a manual.

My uncle trained me as a painter. We cut in everything by hand--never did learn how to use tape on the woodwork. Never read a book on painting. No college for that.

Another uncle taught me to farm at age 14-15. I done all my landscaping myself and even landscaped and designed for others.
Never read a book and never went to college for that.

Being fishing since I was nine years old. I know how to use the wind, the temperature of the air, the temperature of the water, the rainfall ect ect to help that hobby. I was taught how to fish by one of the truly experienced guys I know in the hobby,
Never read a book on fishing but I watched alot of shows on tv and gone to alot of sportsman shows.

The only thing I learned in university was that I didn't want to be there----as you put it above-- I didn't want to learn the same old boring stuff from the same old boring types.

I went to teachers college because I wanted to be a science teacher--it was a means to still use my hands and my senses. I had my first tank when I was 12--which makes me longer in this hobby then you--unfortunately not in salt water due to geographical location---here the stuff was really expensive--and water from Lake Ontario is not good for a marine tank--not good for a fresh water tank either.
Oh I did read some books on aquariums and fish as part of the course.

The first tanks I had in my classes me made from plates of glass and silicone that I was able to scrounge. At one time we had 20 tanks on the go. We raised hamsters, rabbits, bats, mice, rats, squirrels, tarantuas, scorpions, land crabs(which I smuggled back from a trip), Also turtles, frogs, toads, salamanders, meal worms.
Beside tropical fish we had trout, bass, pike, perch.
You can learn alot from watching and caring for these animals.
____________________________________________________
So after 40 years I'm still hanging with guys like you and Waterkeeper--why because its darned interesting and knowledgeable what you guys say and have done in this hobby.
:thumbsup:

BTW
I still don't read books---articles I can hack but I like these forums
:lol:

[tmz]

Learning is a good thing. Quality hands on experience is hard to beat. Formal education provides knowledge that helps to interpret and give meaning to experience in my opinion. Reading about the hobby won't make someone an expert. Reading particularly studies and facts as opposed to musings and theories , education and experience supplement one another .

[Paul B]

I received my auto mechanics experience from a french canadian mechanic who would have me listen to an engine and be able to tell when the bearings were worn on the crankshaft, how to tell the difference between 9/16 and 5/8 bolt by reaching up under the car and feeling it with my fingers ect ect. I changed a motor in my future mother in laws car on the drive way just to impress here a little. It did

Capn, thats great, we have a lot in common. I was also a mechanic. My Dad died when I was 10 and my neighbor owned a junk yard so he gave me a job when I was 12.
I started cutting parts out of cars with a torch when I was about 14 and learned everything internally about cars in that junkyard.
Then I graduated to a gas station where I also worked with one of those old guys that would just make me listen to the engine.
Then I got a job with General Motors as an A rated mechanic.
To this day I have never let anyone touch my car, boat, refrigerator, stove TV , home or anything else. I have never hired any one for anything except dentists, and if I could see in there, I would do that too. :D
I will change the engine (like you in the driveway) and have rebuilt too many engines to count. Transmissions also.
Thats how you learn. Of course you can learn in a mechanic school but then you won't learn that a bent screw on a flywheel cover will cause a leak or the sound of a timing chain about to go.
You want to hear the sound of hundreds of engines so you can tell when something is about to fail. Those Old Timers taught you how to listen to learn.
But I also read books. All sorts of books. Science books, mechanic books, marine biology books, and novels if I have time which I don't anymore.
Capn, I know you won't believe this but when I returned to the states from Nam I was awarded a citation for
(and I think they made this up) "Creativity in a combat envirnment"
I just love to build things

:p
I think thats the biggest problem with kids today, it is much too easy. Growing up, I always had a bicycle. I would go into lots, find bike parts and build a bike. Cars also. Junk yards would sell you a car for $10.00. For a few bucks you could fix the thing up, sell it for a few hundred bucks and build another one. I always had a car also. Life is easy if you are not too lazy and know how to teach yourself a few things.
If you have to depend on other people for all of your knowledge, you are in trouble


:smokin: :p

Have a great day

[reefworldaq]

Hai Paul, I think the Bob is right. After all the nutrient and all the detritus was consume by bacteri. I think all will be foul again or brake down again into amonium because all the think is stay in there. I'm now in try to use the different combination of the system.
First system :
* use 1" sand bed, ATS, Skimmer.
Second System :
* Bare bottom, ATS, Skimmer.
Between two system what did all you think the best option.
Thank's you all.

[Paul B]

I would think the 1" of sand with the skimmer would be the best way to go

[ReefEnabler]

but if I remove my 5" DSB then I won't be able to reach to the bottom of my tank anymore :eek:

[tmz]

<a href=showthread.php?s=&postid=14673462#post14673462 target=_blank>Originally posted</a> by Paul B
I would think the 1" of sand with the skimmer would be the best way to go :) I generally agree with this type of set up, and use it on two of my display tanks, depending on the animals you wan't to keep. The one inch of sand won't support fish that need sand to burrow in or sleep in or most other sand loving creatures.

In my opinion, a deeper sand bed may provide a minimal amount of additional denitrification but may be more of a maintenance headache long term. If you want jawfish, certain wrasses.,pistol shrimp ,certain gobies etc: deeper sand is needed. When deeper sand is used more attention needs to be paid to keeping it alive with sand creatures to insure pathways for nutrients and oxygen sources such as nitrate to move through it. Live deep sand beds can be a very interesting addition to the aquarium. I have one on one of my displays and it has been functioning well for 7 years.

[Paul B]

Ryan, use one of these as I have always done.

:D http://i258.photobucket.com/albums/hh270/urchsearch/plasticbulb.jpg

[sunsetSPS]

I went from DSB to BB and ended up SSB just because I like the natural white look of SB and don't like the bulky look of DSB (I used to have a trim to cover the DSB), DSB just to add weight to my tank. These days we have tons of effective ways to remove nitrate why bother with DSB when I don't feel like it.

[herring_fish]

My old tank setup:
For about 7 years, I ran a plenum and 3” of coral gravel, topped with 4” of coral sand. Mis-labeled or not, this was what people called the Jaubert style bottom. I had an algal turf scrubber so all of my nurturant levels were always zero, even though I drastically over fed.

I did however stop feeding the tank and had the scrubber off line for three months, while I was traveling. Aeration came from a short water fall. There was no skimming and no sump. This is just before I shut down the tank because I was relocating. I didn’t touch the tank in any way, no water changes, no additives, nothing. I didn’t even clean the glass.

At the end of that time, the nurturance weren’t zero but they were low and everything in the tank look great. Well it did after I finally scraped the glass.

When I was moving, I broke down the tank very carefully. The sand had not clumped, nor did the gravel. It basically looked like it did after about 6 months. There was a ¼” layer of detritus at the bottom that was very fine and flat.

My new tank setup:
In talking to one of the owners of Caribsea about my new setup, he suggested, in part, that I use all gravel in my bed. He felt that the water migration is better through gravel and Jaubert wrote of using more gravel in his systems that I originally thoght.

I will use a 55 gallon sump with a plenum and about 6” of gravel. I will all but top it off with a very porous coral rubble. This will provide an area for sponges and small critters to grow and live in safety.

In the main tank, I will simply put sand right on the bottom for cosmetic reasons only.

[Paul B]

Actually Jean Jaubert designed that system because the sand systems were having problems with hydrogen sulfide and so were deep gravel systems.
Unfortunately his systems were not in service for too many years and they were in a public aquarium system. BoB Goemans wrote about configuring them to home aquariums.
The only problem with them is that they don't have much nitrate reducing capabilities. The problems with sand was that there is too little water flowing through the sand and the Jaubert problem was that there was too much water flowing. If you could get just the right size of gravel/sand, it should work perfectly. Or almost.
Herrring-fish, your system with that much gravel may work fine. Only one way to find out.

[elegance coral]

<a href=showthread.php?s=&postid=14565435#post14565435 target=_blank>Originally posted</a> by Paul B
This is the letter Bob just wrote back to me

Quote
"Hi Paul.
Could be those people that keep changing water to reduce nitrate don’t realize that within one to two days after a change the nitrate level returns to the almost the exact level it was before the change. The reason for that is nitrate is flowing back into the bulk water from their sandbed and live rock! Water changes are ‘not’ the proper way to reduce nitrate – getting to the root cause is the way to go and also that of understanding how those bacterium work in substrates of various kinds, depths, and porosity.
Bob"

I agree with this to a point. It's true that in some systems water changes will only cause a temporary reduction in nitrate. Is this due to some newly discovered process or magical bacteria? No. In order for LR and sand to release nitrate into the open water, there has to be a sourse. In order to elevate nitrate levels within days, as suggested above, there needs to be a sizable sourse. That sourse is decomposing organic matter. Better known in the aquarium hobby as detritus. Ammonification takes place through decomposition. Ammonia and nitrite can not escape sand or LR when there is a healthy aerobic layer. Nitrate and nitrogen gas can. The simple solution to reducing the amount of nitrate that can escape these substrates, would be to limit the fuel these bacteria use to produce it. In other words. Keep the sand and LR clean and it can't dump problem causing levels of nitrate into the system.

IMHO. The problem with DSB's is the notion that you can leave them alone indefinitely and they will magically send all decomposing matter, and the substances produced from it, to a parallel universe. When DSB's are left undisturbed for extended periods of time, detritus accumulates. This detritus can accumulate faster than it can be broken down by the bacteria. Eventually you end up with the equivalent of a large rotting grouper carcass on the bottom of your tank.

So......Simply keep the LR and sand clean, and all these problems go away.

[sympley]

Oh, boy this new information is confusing me even more. I'm in a process of upgrading my refugium to even bigger and deeper. Currently I have 10" DSB with fine oolitic sand. I am building a new refugium so that it can handle depth of 14". Now I am not sure what to do? Should I keep building and set up 14" dSB or should I follow the new wave and only go for about 4"????

Some background on my refugium with DSB. It was set up about 9 months ago with only about 6". Nitrates dropped to about 10. No green algae issues. Some cyano issues because I had phosphates, I introduced phosban reactor and for 6 months there were no issues with any algae, or cyano. Everything was very well.

3 months ago I decided to put in more sand in the DSB, since the 6" brought my nitrates from 40's down to about 10 why not, maybe I can drop it even more. Well I added another 4" to 5". Now I am at 10" +. Since I added more depth I started to experience issues with cyano, green algae. I am starting to see wired green algae growing in the crevices on my live rock. My zoos get cover with cyano daily and I need to clean them daily. I have 3 tangs and an angel fish which are picking at the algae all the time and they can't keep up with it. My nitrates are off the chart at about ~60

Not sure what to do now. I am hearing one side saying go deeper hence I want to go 14", and now this which is saying go shallower.

I am even considering to get a denitrator but these are not cheap.

I change phosphate media every 3 weeks!!! I trim my cheato every week, and do WC every other week.

What depth would you guys recommend? Any other suggestions.

[Paul B]

I think your nitrates were going down because of the time the thing had been in operation, not the depth of the sand which I feel is too deep. I think 4" will be fine.

[jenglish]

I think 4-6 inches is what most have luck with and I stick more to the 4 inch side. Just because something works well doesn't always mean more will be better (Jim Beam taught me this lesson). If your nitrates are climbing quickly, you need to look at lowering bioload, decreasing nutrient import or increasing nutrient export. You could get a bigger skimmer, increase your lighting in your fuge and harvest more increase waterchange schedule, reduce feeding or even get rid of a few fish. A bit more flow can help with the algae forming but ultimately you need to deal with the nutrient issue :)

[sympley]

I guess I will re-design my new refugium to only hold approx. 4" and hope for the best.

Is it save to assume that this new discovery will change the way we approach DSB?

[Aquarist007]

<a href=showthread.php?s=&postid=14761100#post14761100 target=_blank>Originally posted</a> by sympley
I guess I will re-design my new refugium to only hold approx. 4" and hope for the best.

Is it save to assume that this new discovery will change the way we approach DSB?

I doubt very much the debate over dsb has been going on for a long time now and probably will continue for a long time into the future.

One excellent point above however the should not be lost is that it is not a question of depth of a dsb rather it is a question of curbing the importing of nitrates to begin with.;)

[herring_fish]

I used the typical Jaubert/Goemans plenum tank bottom for about 7 year in the 90’s. As a side note, I never needed snails. I could look into this area and see it accumulating over time but when I tore the tank down because I was relocating, I found about ¼ inch layer of detritus on the bottom.

I have started my new tank and have heavily feed for about 2 months. Now, I have lots of snails that defecate a tremendous amount of material. Being that I am in the setup stage, I have a mostly bare bottom in parts of the tank, temporarily. I find that I have a thinner layer of this stuff in all of the areas of low water flow and it is blown up when ever the stream of water from the pump is directed onto the rock.

This fresh detritus looks just the same as the 7 year old gray powder that was not consumed by anything in my old tank. I had read Dr. Adey’s book and tried to get bottom feeding critters to eat fresh detritus in my old tank. Admittedly, the plenum was supposed to have been an anaerobic zone so that may have limited the range of bacteria that might have been able to consume it.

Never the less, the detritus had passed through the critters, the aerobic zone and finally into the anaerobic zone. Therefore I thought that what remained had been reduced to an almost inert substance.

Seeing this fresh detritus and how it looks just like the old, I wonder what a layer of several inches of this stuff could do to a tank’s water quality. I also wonder what animals or bacteria could eat it if it was isolated in one place and freely accessible them.

[elegance coral]

<a href=showthread.php?s=&postid=14770182#post14770182 target=_blank>Originally posted</a> by herring_fish
I used the typical Jaubert/Goemans plenum tank bottom for about 7 year in the 90’s. As a side note, I never needed snails. I could look into this area and see it accumulating over time but when I tore the tank down because I was relocating, I found about ¼ inch layer of detritus on the bottom.

I have started my new tank and have heavily feed for about 2 months. Now, I have lots of snails that defecate a tremendous amount of material. Being that I am in the setup stage, I have a mostly bare bottom in parts of the tank, temporarily. I find that I have a thinner layer of this stuff in all of the areas of low water flow and it is blown up when ever the stream of water from the pump is directed onto the rock.

This fresh detritus looks just the same as the 7 year old gray powder that was not consumed by anything in my old tank. I had read Dr. Adey’s book and tried to get bottom feeding critters to eat fresh detritus in my old tank. Admittedly, the plenum was supposed to have been an anaerobic zone so that may have limited the range of bacteria that might have been able to consume it.

Never the less, the detritus had passed through the critters, the aerobic zone and finally into the anaerobic zone. Therefore I thought that what remained had been reduced to an almost inert substance.

Seeing this fresh detritus and how it looks just like the old, I wonder what a layer of several inches of this stuff could do to a tank’s water quality. I also wonder what animals or bacteria could eat it if it was isolated in one place and freely accessible them.

The "fresh" detritus looks just like the "old" because they are one in the same. The detritus in the old tank wasn't 7 years old. The system will continually produce detritus. It is also continually being broken down and dissolved away.

I doubt much of anything could survive in a system that had several inches of detritus on the bottom. Except maybe algae.

Decomposing detritus is constantly releasing substances like nitrate and phosphate into the water. It doesn't take much detritus to reek havoc with water quality.

[a.k.a.Lunchbox]

Very interesting read but after reading this thread I'm still on the fence when it comes to DSB's

[herring_fish]

I had an Algal Turf Scrubber so I never worried about nitrates or phosphates but when I turned it off for 3 months in the 6th year (and cut out the feeding) the water quality stayed pretty good.

So the detritus was being processed after all? Then a ¼ inch max is expectable?

[herring_fish]

.

[herring_fish]

I didn’t think that a UDSB would be a big mechanical filter but when I turned it on, I founded that, the way that I had set mine up, it was. This wouldn’t be important if I used a skimmer or didn’t feed so much. Optimally, I would like it if I could get powdered and live food to stay suspended in the water column until it is consumed by the corals or it rots. Then the algal scrubber would take up the nutrients.

I am tearing the UDSB down but I’m keeping the plenum and reducing the bed to 4 inches of coral gravel. Then I will fill the rest of the 55 gallon refugium with coral rubble. I have turned off the reverse flow pump but I am leaving the plumbing in place. My thought here is that I can periodically blow the detritus out of the bottom of the tank, there by exporting it without filtering it out too early.

[Gravesj1s]

This has been interesting to say the least.

I ,too tried the plenum based on the Jaubert theory back in the 90's also, noting the detritus accumulation under the bottom plate.However I also noticed when I broke it down the temperature in the substrate was considerably warmer than the tank water. This has really got me wondering about the Hovanec article.
In his experiment the temperature was uncontrolled and ran without heaters. It would make sense that the finesand would have a certain (R) value, maitaining a more stable temperature in the substrate. From what I have read metalbolic rates in thge substrate are sensitive to temperature. It would make sense a larger grain size would have a lesser (R) value , and fluncuate temperature more in the substrate through circulation within the watercolumn .
This of course is just a "possible theory" and thought it was worth bringing to discussion.
anyone thoughts out their?
-Graves

[Aquarist007]

<a href=showthread.php?s=&postid=14772461#post14772461 target=_blank>Originally posted</a> by a.k.a.Lunchbox
Very interesting read but after reading this thread I'm still on the fence when it comes to DSB's

that's why I went to running a remote deep sand bed;)

[herring_fish]

What is the meaning and advantage of a REMOTE deep sand bed?

[elegance coral]

<a href=showthread.php?s=&postid=14806924#post14806924 target=_blank>Originally posted</a> by herring_fish
What is the meaning and advantage of a REMOTE deep sand bed?

The meaning is simply a sand bed that's not in the display. It's in a container that's positioned "remotely" from the display, but plumed into the same system.

The advantage, for me anyway, is the ability to keep it clean. A deep sand bed in the display with rocks stacked on top of it, is a ticking time bomb. Detritus builds up within the sand and there's not much you can do about it. Over time water quality gets worse and worse. With a remote DSB you can filter the water before it reaches the sand bed, greatly reducing the amount of detritus that accumulates. There's no need to stack rocks on top of a RDSB making vacuuming the sand very easy. You can get the nitrate reduction without the negative effects of a DSB in the display.

[herring_fish]

Oh, a sand bed in your sump, a secondary refugium or even a tertiary tank just for the sand bed.

Good thanks

[Whys]

Paul,

Your central premise is that all DSBs are inherently flawed. That is not a resolved debate and points to author bias. Given that you admit to not having much first had experience with a DSB, your choice of thread and theory seems suspect.

To be clear, "anoxic" and "anaerobic" are two sides of the same coin. Anoxic means devoid of oxygen. Anaerobic means metabolism (life) without oxygen. Thus the bottom layer of a DSB can become anoxic and any bacteria living there would be anaerobic.

If you are going to purposefully detract, thru argumentative fallacy, an element of this hobby you choose not to engage in, then please at least keep your facts straight.

Thank you. :)

[Aquarist007]

<a href=showthread.php?s=&postid=14929952#post14929952 target=_blank>Originally posted</a> by Whys
Paul,

Your central premise is that all DSBs are inherently flawed. That is not a resolved debate and points to author bias. Given that you admit to not having much first had experience with a DSB, your choice of thread and theory seems suspect.

To be clear, "anoxic" and "anaerobic" are two sides of the same coin. Anoxic means devoid of oxygen. Anaerobic means metabolism (life) without oxygen. Thus the bottom layer of a DSB can become anoxic and any bacteria living there would be anaerobic.

If you are going to purposefully detract, thru argumentative fallacy, an element of this hobby you choose not to engage in, then please at least keep your facts straight.

Thank you. :)

I am shocked at reading a post like this.

PaulB has probably more experince in this hobby then you have years on this earth.
This kind of post does not hold much water with experienced guys like Paul ,I am sure, but what it does do is deter them from posting on here or bothering with inexperienced guys like you, me and the many others.
And this is what bothers me in that I have the upmost respect and regard for someone as experienced and successful as Paul and the very few other reefers that I would put in the same boat or class as him.

[JoelNB]

<a href=showthread.php?s=&postid=14929952#post14929952 target=_blank>Originally posted</a> by Whys
Your central premise is that all DSBs are inherently flawed.
Not presuming to answer for Paul, but I'm not sure that's what it was. What I have taken away from this thread is the idea that a deep sand bed needs to be the right size, with density considered, and not just a big pile of sand. I still use a DSB.

[Paul B]

Your central premise is that all DSBs are inherently flawed. That is not a resolved debate and points to author bias. Given that you admit to not having much first had experience with a DSB, your choice of thread and theory seems suspect.

Capn, although I appreciate your trying to defend me I am a big boy and actually like it when someone questions my beliefs.
I am human and do make mistakes. Maybe Whys can educate me.

Whys, you are correct in saying I do not have much experience running DSBs but my first system was a DSB 25 years before they were commonly used. I also was not in a coma since they have been invented. I even know some of the authors that advocated them in the eightees and ninetees.

I stand by what I said in that they are flawed. The technology as to how they work is not flawed, but the technology as to what keeps them working is flawed.

DSBs have been around for 20 years or so, where are the tanks that ran these systems 20 or even 15 years ago?
There are a handful of even 10 year old DSBs. I know of two.

Any substrait in a closed tank will fail eventually. Even my RUGF.
The difference is the size of the particles. Smaller particles will clog sooner. The theory of a DSB is that organisms populate the sand and burrow down to the lower levels there by letting in water to be treated by the bacteria to remove nitrate.
Everyone knows that will work, initially. As the bed matures and detritus accumulates, which is composed largely of dead bacteria, the anerobic or anoxic areas (yes I know they are different and I called Bob Goemans to tell him of his mistake)
Can not support any life except for certain bacteria.
Pods, worms, crabs, or anything else can not live there nor can they visit there even for a few seconds. Eventually, that layer will not have any water circulation and it will become anoxic. Totally useless for our purposes because no water can get there to be treated. There is no animal life there due to no oxygen. The spaces between the sand grains will clog with dead bacteria and detritus and if you drilled a hole in the bottom of such a tank, I doubt any water would leak out.
The waste materials that get treated in a DSB do not magically get beemed to another dimension. There is always some solid waste materials in an aquarium and it does not take much of this to clog sand.
Another thought is while these organisms will dig in the substrait, after a few years many of these minute animals will no longer re produce. After a short while most of the bed will be very barron.
So then Whys, what part of the theory of DSBs is not flawed?[

QUOTE]That is not a resolved debate and points to author bias.[/QUOTE]

I certainly am biased. But I am willing to learn. I have stated how I came to this conclusion. I have been studying these things for quite some time but if you have another theory as to how a DSB will work for 20, 30, or 40 years, I would love you to educate me on it. If it sounds reasonably maybe I will tear down my tank and install one.

[Aquarist007]

<a href=showthread.php?s=&postid=14931915#post14931915 target=_blank>Originally posted</a> by Paul B
Capn, although I appreciate your trying to defend me I am a big boy and actually like it when someone questions my beliefs.
I am human and do make mistakes. Maybe Whys can educate me.

Whys, you are correct in saying I do not have much experience running DSBs but my first system was a DSB 25 years before they were commonly used. I also was not in a coma since they have been invented. I even know some of the authors that advocated them in the eightees and ninetees.

I stand by what I said in that they are flawed. The technology as to how they work is not flawed, but the technology as to what keeps them working is flawed.

DSBs have been around for 20 years or so, where are the tanks that ran these systems 20 or even 15 years ago?
There are a handful of even 10 year old DSBs. I know of two.

Any substrait in a closed tank will fail eventually. Even my RUGF.
The difference is the size of the particles. Smaller particles will clog sooner. The theory of a DSB is that organisms populate the sand and burrow down to the lower levels there by letting in water to be treated by the bacteria to remove nitrate.
Everyone knows that will work, initially. As the bed matures and detritus accumulates, which is composed largely of dead bacteria, the anerobic or anoxic areas (yes I know they are different and I called Bob Goemans to tell him of his mistake)
Can not support any life except for certain bacteria.
Pods, worms, crabs, or anything else can not live there nor can they visit there even for a few seconds. Eventually, that layer will not have any water circulation and it will become anoxic. Totally useless for our purposes because no water can get there to be treated. There is no animal life there due to no oxygen. The spaces between the sand grains will clog with dead bacteria and detritus and if you drilled a hole in the bottom of such a tank, I doubt any water would leak out.
The waste materials that get treated in a DSB do not magically get beemed to another dimension. There is always some solid waste materials in an aquarium and it does not take much of this to clog sand.
Another thought is while these organisms will dig in the substrait, after a few years many of these minute animals will no longer re produce. After a short while most of the bed will be very barron.
So then Whys, what part of the theory of DSBs is not flawed?[

QUOTE]That is not a resolved debate and points to author bias.

I certainly am biased. But I am willing to learn. I have stated how I came to this conclusion. I have been studying these things for quite some time but if you have another theory as to how a DSB will work for 20, 30, or 40 years, I would love you to educate me on it. If it sounds reasonably maybe I will tear down my tank and install one. [/QUOTE]

Paul, I can fully appreciate the fact that you are tough as nails and if someone picks a fight with you that's fine by you;)

I just don't like negative and disrespectful posts period:strooper:

[tmz]

No need for acrimony;it detracts from discussion more than any position a person may take.

Sand is just sand and not worth hard feelings.

It is good at providing a lot of surface area for bacteria to colonize in a relatively small space as compared to other substrates or even live rock. I don't think it necessarily clogs if sand critters are maintained. Without them movement of nutrients and detritus as well or any organic carbon source for bacteria just won't happen so there may not be anything downt there to feed bacteria or to rot.

Much of the new thinking on dsbs is that a good deal of denitrification may occur in the first inch or two of sand bed obviating the need for greater depth purely for denitrification.

I have a 7 yr old dsb and several shallow bed tanks and a bare bottom. In my opinion they all can work. Deep beds do provide habitat for certain fishes and other critters and microfuana not available in shallow or bare bottom tanks. They also provide enhanced surface areas and require some maintenance.

It is largely a matter of personal choice and aesthetic preference and the critters you want to keep.

[jenglish]

I do know of a few long running DSBs that are ran with ATS systems. I think one of the problems with saying a technique will or won't work based an example is these are complex systems. There are so many variables involved. Do the DSBs I know of work because of their depth, the microfauna involved.... or is it the ATS..... or is it the sheer volume of the system providing stability (I am thinking of the system at Inland Aquatics in Terre Haute IN).

I think DSBs can be a benefit. I think they need to be cleaned just like any other substrate. You can and in my opinion should vacuum a DSB, even one with oolitic aragonite. It still gets poop in it :) You shouldn't do it all at once like some may do with CC or gravel... but removing unbroken down detritus can remove things before they are bound up PO4.

It does make me wonder about a silcate DSB.... could this offer the benefits of DSB w/o the ability to bind up PO4?

[Paul B]

Capn, it was never a fight, just an enlightening conversation by a member. I am hoping we will hear more from Whys.

Much of the new thinking on dsbs is that a good deal of denitrification may occur in the first inch or two of sand bed obviating the need for greater depth purely for denitrification.

I totally agree with this. A DSB a few inches deep should work fine. I don't think some of those 6" beds will fare so well. They may sit there for years and not cause any harm but I doubt the lower layers are doing anything except take up space.

Also it is true (as was said) that these systems are much too variable to say what will and will not work. I am mainly going on the amount of people in the hobby and the length of time various systems last. I think a SSB or BB should last the longest but they also have the least capacity to control nitrates and this task will need to be performed some other way.
Again, I never said DSBs don't work. I said I don't think they will last for long. I am older than most here and ten years is not a long time to me. Almost all fish live twice that length of time.

I love these exchanges of information and never consider any of them a fight. :D

[jasonrp104]

I must've misunderstood somewhere in my reading. I was under the assumption that for the most part DSBs needed to be left undisturbed BUT to help with thier longevity, it was good to jam holes in them once in awhile.

Every other water change, I'll take my turkey baster and stab my sandbed right to the glass in a few random areas. I figured yes, it would kill some bacteria but it would also help keep the deeper parts from becoming too nasty. My sandbed is relatively new but it is already de-nitrifying and full of critters. Should I stop? To me, it makes sense to do it

[herring_fish]

Ok We talk about reducing nutrients with sand deep beds but what about their ability to stabilize water chemistry? I am re-staring a tank after a long layoff and am having problems with my pH, KH and calcium etc. My old tank had a plenum, 3” of coral gravel, 4” of coral sand and live rock. I also used an Algal Turf Scrubber (ATS).

With this set up, I never had any problems of any kind, once it matured. This time I have the same ATS but I have been playing around with different sand configuration, varying from almost nothing to having 8” of gravel in a 55 G sump and back again. I reached the point of stability much faster in my old tank, than the time that I have invested in my new one and it hasn’t come yet.

I know that stirring up large amounts of sand can cause wild fluctuations in water chemistry and I can now attest to that. Since I have an ATS, I don’t worry about nutrients. I have never had any test read anything above zero in my old tank and the same is true of the new one. My old tank never ran very high calcium or pH levels like I was dosing but it never tested low. It was always completely stable, no mater how much I feed the tank or how inconsistently I did so.

Therefore I wonder how best to construct a bed to maximize the desolation of aragonite. I really can’t say how well my old sand bed processed nutrients. Regardless of whether my old sand bed was of optimal design, it seems to have become the source great stability for 8 years.

So if I don’t care about nutrients, what should I do?

[jenglish]

<a href=showthread.php?s=&postid=14933459#post14933459 target=_blank>Originally posted</a> by jasonrp104
I must've misunderstood somewhere in my reading. I was under the assumption that for the most part DSBs needed to be left undisturbed BUT to help with thier longevity, it was good to jam holes in them once in awhile.

Every other water change, I'll take my turkey baster and stab my sandbed right to the glass in a few random areas. I figured yes, it would kill some bacteria but it would also help keep the deeper parts from becoming too nasty. My sandbed is relatively new but it is already de-nitrifying and full of critters. Should I stop? To me, it makes sense to do it

THere are those that believe you should never disturb a DSB and those who think they need to be regularly vacuumed.

[Bri Guy]

I think this is a great thread, but have a question.

So far the discussion has all been from an experience view, what about the actual chemistry here.

NH₄ turns into NO₃ which then turns into NO₂ this we know, but then thats where the road splits.

Chemically what are the 2 they are turning into? Does one bacteria take one more oxygen and make nitrogen gas? and the other bacteria takes the rest of the oxygen away and adds hydrogen back to make NH₄ ?

Can anybody verify what the bacteria are doing chemically at the road split?

thankx

[gasman059]

I not only agree wholeheartedly but have experience DSB issues in the past.

It is not how but when an older tank with a true DSB(4-5) will crash since we don't really stay on top of it.

No difference that a UG filter(I've used them) it too will fail if factors such as feeding, flwed circulation, meds,and gravel cleaning are not performed religiuosly.

Natural nitrate reduction thru a DSB is IMHO a thing of the past- if that will and is gonna be an issue in your future tanks u should consider another denitrification process from the get go such as a reactor.

Recent tank includes a 1-2 inch large grain media.

[Paul B]

I think we will always have NNR but we will get better at it.
For now there is no perfect system, the bacteria have a mind of their own and don't always want to help us.

[Aquarist007]

<a href=showthread.php?s=&postid=14936650#post14936650 target=_blank>Originally posted</a> by gasman059
I not only agree wholeheartedly but have experience DSB issues in the past.

It is not how but when an older tank with a true DSB(4-5) will crash since we don't really stay on top of it.



Sorry for asking such a basic question as I probably reach your kneee caps with experience compared to you guys.
My deep sand bed is relatively new(2.5 years) and I have not done any maintenance on it other then to adjust flow rates through the refugium.
What should I be doing to "stay on top of it"

[Paul B]

What should I be doing to "stay on top of it"

Try not to live too long and it will be fine :lol:

It is not even 3 years old so it should be fine for 7 more years as far as I can tell.

[Aquarist007]

<a href=showthread.php?s=&postid=14937234#post14937234 target=_blank>Originally posted</a> by Paul B
Try not to live too long and it will be fine :lol:

It is not even 3 years old so it should be fine for 7 more years as far as I can tell.

great --it can be someone elses problem by then---I'll probably have moved on to the tank in the sky:lol:

[Paul B]

I'll probably have moved on to the tank in the sky

And I will be right next to you.
I wonder if they only let you keep "Angel Fish" in heaven :lol:

Probably no Blue Devils :eek1:

[Aquarist007]

<a href=showthread.php?s=&postid=14937393#post14937393 target=_blank>Originally posted</a> by Paul B
And I will be right next to you.
I wonder if they only let you keep "Angel Fish" in heaven :lol:

Probably no Blue Devils :eek1:

Sorry to be the bearer of bad news but I don't think you will be allowed in there----not with all the sea food you have "forked" speared or swallowed whole in your life:lol: :rollface: :lol:

[tmz]

<a href=showthread.php?s=&postid=14936415#post14936415 target=_blank>Originally posted</a> by Bri Guy
I think this is a great thread, but have a question.

So far the discussion has all been from an experience view, what about the actual chemistry here.

NH₄ turns into NO₃ which then turns into NO₂ this we know, but then thats where the road splits.

Chemically what are the 2 they are turning into? Does one bacteria take one more oxygen and make nitrogen gas? and the other bacteria takes the rest of the oxygen away and adds hydrogen back to make NH₄ ?

Can anybody verify what the bacteria are doing chemically at the road split?

thankx I don't think the road splits on the chemistry of denitrifiction as it does on wether deep sand beds provide suitable long term anoxic environments for the heterotrophic bacteria that perform it .
The chemistry is the same wether denitrifiction occurs in a shallow bed or a deep one, The debate is about where it will most efficiently occur
As you may know, these bacteria in the absence of O2 turn to the O3 in NO3 for energy . The end product is harmless free nitrogen gas which returns to the athmosphere or may be fixed back into an organic form . Cyanobacteria can fix nitrogen for example .It seems this notion of a new nitrate theory is based on the assumption that some new formerly unknown strain of bacteria may exist that fixes this free nitrogen.

[Aquarist007]

<a href=showthread.php?s=&postid=14937663#post14937663 target=_blank>Originally posted</a> by tmz
I don't think the road splits on the chemistry of denitrifiction as it does on wether deep sand beds provide suitable long term anoxic environments for the heterotrophic bacteria that perform it .
The chemistry is the same wether denitrifiction occurs in a shallow bed or a deep one, The debate is about where it will most efficiently occur
As you may know, these bacteria in the absence of O2 turn to the O3 in NO3 for energy . The end product is harmless free nitrogen gas which returns to the athmosphere or may be fixed back into an organic form . Cyanobacteria can fix nitrogen for example .It seems this notion of a new nitrate theory is based on the assumption that some new formerly unknown strain of bacteria may exist that fixes this free nitrogen.

Tom---can you point me to some readings on this?

[gasman059]

The chemistry is the same wether denitrifiction occurs in a shallow bed or a deep one, The debate is about where it will most efficiently occur
;)
this should help.
http://www.reefkeeping.com/issues/2008-06/newbie/index.php

[Paul B]

Sorry to be the bearer of bad news but I don't think you will be allowed in there----not with all the sea food you have "forked" speared or swallowed whole in your life

In California we had the best barbecued oysters I have ever eaten. From now on, they will be on my plate more often.

OK back to the topic

[Bri Guy]

<a href=showthread.php?s=&postid=14937663#post14937663 target=_blank>Originally posted</a> by tmz
I don't think the road splits on the chemistry of denitrifiction as it does on wether deep sand beds provide suitable long term anoxic environments for the heterotrophic bacteria that perform it .

Im actually quoting the artical here...

Quote:
The resulting nitrate
is then acted upon in a lower area of
the substrate that contains little or no
oxygen, generally referred to as the
anaerobic area. It is there that we found
two different classes of bacteria following
two different paths—one path reducing
nitrate to ammonium only (the primary
alga nutrient), and the other reducing it
to nitrogen.
UnQuote:

It says that one reduces NO₂ to NH₄ and one turns it into nitrogen.

And thats the spin on this artical, Is nitrate actually turned back into ammonium???

[tmz]

That's the split in the road. Does this second type of bacteria really exist in a deep sand bed? BTW Here's the second paragraph of my post.

As you may know, these bacteria in the absence of O2 turn to the O3 in NO3 for energy . The end product is harmless free nitrogen gas which returns to the athmosphere or may be fixed back into an organic form . Cyanobacteria can fix nitrogen for example .It seems this notion of a new nitrate theory is based on the assumption that some new formerly unknown strain of bacteria may exist that fixes this free nitrogen.

[Paul B]

It seems this notion of a new nitrate theory is based on the assumption that some new formerly unknown strain of bacteria may exist that fixes this free nitrogen.

It is not a new unknown strain of bacteria but the regular airobic bacteria that is all over a tank which converts ammonia to nitrate.
I think he is saying that this process can go back and fourth between the different types of bacteria. At first in the shallow layers of a substrait the ammonia is converted to nitrate which we all know. Then in the lower layers the nitrate is converted to nitrogen. The nitrogen can again be converted back to ammonia which in turn gets turned back to nitrate.
Too many processes for me to get my mind fully around. But I do know that many people with DSBs have nitrate problems, maybe this is why

[Aquarist007]

<a href=showthread.php?s=&postid=14941561#post14941561 target=_blank>Originally posted</a> by Paul B
It is not a new unknown strain of bacteria but the regular airobic bacteria that is all over a tank which converts ammonia to nitrate.
I think he is saying that this process can go back and fourth between the different types of bacteria. At first in the shallow layers of a substrait the ammonia is converted to nitrate which we all know. Then in the lower layers the nitrate is converted to nitrogen. The nitrogen can again be converted back to ammonia which in turn gets turned back to nitrate.
Too many processes for me to get my mind fully around. But I do know that many people with DSBs have nitrate problems, maybe this is why

I thought there were three strains
aerobic converting ammonia to nitrites
anerobic converting nitrites to nitrates
anoxic converting the nitrates to nitrogen gas.

[tmz]

<a href=showthread.php?s=&postid=14941561#post14941561 target=_blank>Originally posted</a> by Paul B
It is not a new unknown strain of bacteria but the regular airobic bacteria that is all over a tank which converts ammonia to nitrate.
I think he is saying that this process can go back and fourth between the different types of bacteria. At first in the shallow layers of a substrait the ammonia is converted to nitrate which we all know. Then in the lower layers the nitrate is converted to nitrogen. The nitrogen can again be converted back to ammonia which in turn gets turned back to nitrate.
Too many processes for me to get my mind fully around. But I do know that many people with DSBs have nitrate problems, maybe this is why ;) Hello Paul.

To be clear, it is generally understood that nitifiers(the bacteria that take waste material and make nitrate ) are aerobic and denitrifiers(those that break down nitrate NO3) are anerobic.

Many people have nitrate problems with bare bottom tanks, shallow substrates and deep substrates.Many don't . There are too many other variables to conclude one type of substrate is better than an other for a particular system.

One turn this debate has taken is wether or not depth of sand bed is an advantage for anerobic denitrifying bacteria. In a well kept bed with proper fuana , it could be in my opinion.This debate has been going on for years and is nothing new.

The second related point for debate is the claim to this newly found or newly mused strain of anerobic bacteria that fixes free nitrogen gas to hydrogen and thus adds it back to the organic pool as ammonia/ammonium. Does this non photosynthetic bacterium exist or is it merely a contrivance to support a position opposing the use of deep substrate ? Has it been seen under microscope? How much ammonium does it produce.How does it do that? If it's been identified some facets of it's behavior or chemistry must have been observed;what are they? Without more definitive information, this doesn't seem to be a very complete or useful theory to me.

[tmz]

OK , it's been a while ; so I reread the whole article again.

There is a lot of"possibly", "feasible" and"may be" mixed in with seemingly more assertive sentences about a 2nd pathway for anaerobic bacterial activity which are then subtlety qualified.

My original take on it as reasoned speculation was generous. It's mostly a restatement of denitrification as we know it with a confusing side trip attempting to distinguish between anaerobic and anoxic areas.
Areas are full of oxygen or anoxic(devoid of oxygen to a greater or lesser degree). Metabolism/bacterial activity is either aerobic(using oxygen for energy) or anaerobic (occurring in the absence of oxygen)or degrees in between.BTW,Whys noted this in an earlier post.
There are no anaerobic areas; there are anoxic areas in which anaerobic bacterial activity predominates. So a strategy encouraging more anaerobic areas and less anoxic areas, as the author suggests in one of his central positions, makes no sense at all to me.Perhaps he means areas that are not totally anoxic but I don't really know.

There is also nothing in the article to suggest that the existence of the second pathway nitrogen fixing bacteria deep in the sandbed is anything but pure imagination. The argument that algae persist at low nitrate levels is attributable to some unknown bacteria creating ammonium in an anoxic area is thin and ignores the whole issue of phosphate limitation in microalgae growth. Even if phosphate didn't play such a central role in nuisance algae growth , any ammonium or ammonia could simply come from decomposition of organic materials anywhere in the tank.

Nothing new here; and, the old is not very clearly stated nor comprehensive as well as a bit obfuscatory and misleading,in my opinion.

[Paul B]

Nothing new here; and, the old is not very clearly stated nor comprehensive as well as a bit obfuscatory and misleading,in my opinion.

Yes, but if it was clear, we would have nothing to talk about :lol:

[Aquarist007]

"obfuscatory " I love reading your posts Tom--there is always a neat new word in it.

I'm going to change my avitar to Capn' Obfuscatory much more fitting personally and I am sure there are alot of others on here that would agree :)

[Paul B]

"obfuscatory

That ain't a word, it's a disease, I once went out with a girl that had a bad case of odfuscatory :D

I knew I should have went to college :eek1:

[Aquarist007]

<a href=showthread.php?s=&postid=14943894#post14943894 target=_blank>Originally posted</a> by Paul B
That ain't a word, it's a disease, I once went out with a girl that had a bad case of odfuscatory :D

I knew I should have went to college :eek1:

oh my you went out with her because she was a

oops I better pm you:lol:

[tmz]

I met lots of obfuscating young ladies in college. Plenty of professors too.

[Aquarist007]

<a href=showthread.php?s=&postid=14944586#post14944586 target=_blank>Originally posted</a> by tmz
I met lots of obfuscating young ladies in college. Plenty of professors too.

too much information:lol:

[Paul B]

OK I looked it up. Yep I did go out with some girls like that

"To make so confused or opaque as to be difficult to perceive or understand"

[herring_fish]

Let’s set aside ammonia, nitrite, nitrate and phosphates for just one moment. Let use instead thing about pH KH Calcium and trace elements. Does anyone have any thoughts on a bed that is placed in the tank for the stabilization of water chemistry only?

Bacteria still works to brake down and dissolve a potion of the sand which serves to stabilizes these parameters regardless of whether the nutrients are processed. Is that assumption true?

How can I best take advantage or that?

[Paul B]

Bacteria still works to brake down and dissolve a potion of the sand which serves to stabilizes these parameters regardless of whether the nutrients are processed. Is that assumption true?

My substrait of dolomite had been in the tank for longer than 40 years, I don't notice any of it breaking down yet. If it did it would certainly not be enough to affect water chemistry.

[tmz]

<a href=showthread.php?s=&postid=14948282#post14948282 target=_blank>Originally posted</a> by herring_fish
Let’s set aside ammonia, nitrite, nitrate and phosphates for just one moment. Let use instead thing about pH KH Calcium and trace elements. Does anyone have any thoughts on a bed that is placed in the tank for the stabilization of water chemistry only?

Bacteria still works to brake down and dissolve a potion of the sand which serves to stabilizes these parameters regardless of whether the nutrients are processed. Is that assumption true?

How can I best take advantage or that? :) I don't think bacteria break down aragonite. The sand is largely precipitated calcium carbonate. It will dissolve at lower ph. Ph drops may occur in a bed as the water in the bed becomes more acidic from waste that is processing.

[tmz]

<a href=showthread.php?s=&postid=14947072#post14947072 target=_blank>Originally posted</a> by Paul B
OK I looked it up. Yep I did go out with some girls like that

"To make so confused or opaque as to be difficult to perceive or understand" :) Thanks for clearing that up Paul. Scott was getting me in trouble.

[herring_fish]

<a href=showthread.php?s=&postid=14948539#post14948539 target=_blank>Originally posted</a> by tmz
:) I don't think bacteria break down aragonite. The sand is largely precipitated calcium carbonate. It will dissolve at lower ph. Ph drops may occur in a bed as the water in the bed becomes more acidic from waste that is processing.

Yes that is what I mean. I know that the Upside Down Sand Bed does have noticeable dissolution of aragonite that has to be replenished periodically.

[MattL]

<a href=showthread.php?s=&postid=14942032#post14942032 target=_blank>Originally posted</a> by capn_hylinur
I thought there were three strains
aerobic converting ammonia to nitrites
anerobic converting nitrites to nitrates
anoxic converting the nitrates to nitrogen gas. It seems there is a general misconception in this thread.

When dealing with the nitrogen cycle in a reef, it may be assumed that there are nitrifiers and denitrifiers*.

Nitrifiers oxidize ammonia to nitrite, and then separately nitrite to nitrate. These bacteria are aerobic autotrophs. They are aerobic in that oxygen is the terminal electron acceptor, and autotrophic in that they use inorganic carbon (alkalinity) as their carbon source. Ammonia or nitrite, depending on the bacteria, are the electron donors. These bacteria are always aerobic, as oxygen must be the terminal electron acceptor.

Denitrifiers use a variety of pathways to reduce nitrate to ammonia or nitrogen gas. These bacteria are anaerobic bacteria, in that nitrate (and not oxygen) is the terminal electron acceptor. I will have to go check, but from a reefkeeping perspective, these bacteria are also likely to be exclusively heterotrophs, meaning they must use organic carbon as their carbon source. The organic carbon also serves as the electron donor and energy source.

While denitrifying bacteria are anaerobic, they live in anoxic (not anaerobic regions). This is where people tend to get confused.

Microorganisms are aerobic or anaerobic depending on whether they use oxygen or another oxidized molecule as the terminal electron acceptor. Waters are oxic or anoxic depending on whether dissolved oxygen is present.

Waters that are anaerobic not only lack dissolved oxygen, but a suitable electron acceptor. So in our tanks, this would have to be a region depleted of nitrate and sulfate and iron and so on, which is highly unlikely. So from a reefkeeping perspective, our waters are oxic or anoxic (and not likely anaerobic).

I hope this clears things up,

Matt:cool:

* The chances of there being nitrogen fixing bacteria actually fixing nitrogen are small, simply due to the prevalence of organic and inorganic nitrogen in our tanks. Nitrogen fixers, if given the chance, will rely on any other nitrogen source other than dinitrogen simply because nitrogen fixation is such an energy intensive process. Someone else mentioned the ammonox process a while back, but this process requires super high concentrations of ammonia that are unlikely to be seen in our reefs.

[Aquarist007]

<a href=showthread.php?s=&postid=14949072#post14949072 target=_blank>Originally posted</a> by MattL
It seems there is a general misconception in this thread.

When dealing with the nitrogen cycle in a reef, it may be assumed that there are nitrifiers and denitrifiers*.

Nitrifiers oxidize ammonia to nitrite, and then separately nitrite to nitrate. These bacteria are aerobic autotrophs. They are aerobic in that oxygen is the terminal electron acceptor, and autotrophic in that they use inorganic carbon (alkalinity) as their carbon source. Ammonia or nitrite, depending on the bacteria, are the electron donors. These bacteria are always aerobic, as oxygen must be the terminal electron acceptor.

Denitrifiers use a variety of pathways to reduce nitrate to ammonia or nitrogen gas. These bacteria are anaerobic bacteria, in that nitrate (and not oxygen) is the terminal electron acceptor. I will have to go check, but from a reefkeeping perspective, these bacteria are also likely to be exclusively heterotrophs, meaning they must use organic carbon as their carbon source. The organic carbon also serves as the electron donor and energy source.

While denitrifying bacteria are anaerobic, they live in anoxic (not anaerobic regions). This is where people tend to get confused.

Microorganisms are aerobic or anaerobic depending on whether they use oxygen or another oxidized molecule as the terminal electron acceptor. Waters are oxic or anoxic depending on whether dissolved oxygen is present.

Waters that are anaerobic not only lack dissolved oxygen, but a suitable electron acceptor. So in our tanks, this would have to be a region depleted of nitrate and sulfate and iron and so on, which is highly unlikely. So from a reefkeeping perspective, our waters are oxic or anoxic (and not likely anaerobic).

I hope this clears things up,

Matt:cool:

* The chances of there being nitrogen fixing bacteria actually fixing nitrogen are small, simply due to the prevalence of organic and inorganic nitrogen in our tanks. Nitrogen fixers, if given the chance, will rely on any other nitrogen source other than dinitrogen simply because nitrogen fixation is such an energy intensive process. Someone else mentioned the ammonox process a while back, but this process requires super high concentrations of ammonia that are unlikely to be seen in our reefs.

Thank you for accepting my invitation to join this thread Matt.

From what I have just read I am interpreting(from a very basic knowledge) that our deep sand beds are not anoxic and therefore can't support detrifying bacteria. Further is they can't support the dentrfiers then they are not doing the job they are reported to do--reduce nitrates.
This could explain the failure of deep sand beds overtime in that nitrates simply saturate the deep layers gradually moving up to the top layers where the nitrates start being introduced back into the water column?

[MattL]

<a href=showthread.php?s=&postid=14949317#post14949317 target=_blank>Originally posted</a> by capn_hylinur
Thank you for accepting my invitation to join this thread Matt.

From what I have just read I am interpreting(from a very basic knowledge) that our deep sand beds are not anoxic and therefore can't support detrifying bacteria. Further is they can't support the dentrfiers then they are not doing the job they are reported to do--reduce nitrates.
This could explain the failure of deep sand beds overtime in that nitrates simply saturate the deep layers gradually moving up to the top layers where the nitrates start being introduced back into the water column? Before I begin, bear in mind there was a small error in the copy of this response I sent you personally that I corrected here, so for the last few sentances, use what I wrote here.

Just to clarify, sand beds are most likely lacking in dissolved oxygen (anoxic). Casual observance and probing with an ORP meter can verify this.

Sand beds are not anaerobic. Again, anaerobic means a lack of all suitable electron acceptors, not just oxygen. I'm going to guess that between the nitrate, sulfate, and iron in our tanks, our sand beds are only anoxic, not anaerobic.

Just to summarize, for bacteria:
Aerobic Bactera live in Oxic waters
Anaerobic Bacteria live in Anoxic waters
Anaerobic Bacteria live in Anaerobic waters

For waters
Oxic: O2, SO4--, NO3-, Fe+++
Anoxic: SO4--, NO3-, Fe+++
Anaerobic: None.

As for the failure of deep sand beds, there can be many reasons. Anaerobic bacteria are notoriously finicky and difficult to culture, grow, and control. Back in 2001, I wrote about the shallow sand bed on another message board and my preference for using it, as I feared that creating large anoxic zones in my tank with a deep sand bed could lead to potential catastrophe. I still use a fairly shallow sand bed, and rely on other means to get rid of nitrate.

Also, denitrifers are heterotrophs. Unlike our autotrophic nitrogen oxidizers, they cannot take alkalinity from the water to use as a carbon source for cell synthesis. If the deep sand bed is carbon limitting, then denitrification would be limitted. The whole philosophy behind ethanol dosing (which, for the record, I swore would never work, but I now realize I was wrong and that our tanks are carbon limitted) is that denitrification is being inhibited by the lack of a readily available carbon substrate, such as ethanol.

Matt:cool:

[Aquarist007]

boy nothing like an excellent on line class in microbiology--great posts Matt or Dr. Matt.

Can one assume then that the anerobic bacteria that live in the anoxic areas of the dsb and live rock perform both reduction reactions of nitrites to nitrates and then nitrates to nitrogen?
Or are there two strains of anerobic bacteria that perform these two functions?

[Aquarist007]

boy nothing like an excellent on line class in microbiology--great posts Matt or Dr. Matt.

Can one assume then that the anerobic bacteria that live in the anoxic areas of the dsb and live rock perform both reduction reactions of nitrites to nitrates and then nitrates to nitrogen?
Or are there two strains of anerobic bacteria that perform these two functions?

[Aquarist007]

boy nothing like an excellent on line class in microbiology--great posts Matt or Dr. Matt.

Can one assume then that the anerobic bacteria that live in the anoxic areas of the dsb and live rock perform both reduction reactions of nitrites to nitrates and then nitrates to nitrogen?
Or are there two strains of anerobic bacteria that perform these two functions?

[Aquarist007]

boy nothing like an excellent on line class in microbiology--great posts Matt or Dr. Matt.

Can one assume then that the anerobic bacteria that live in the anoxic areas of the dsb and live rock perform both reduction reactions of nitrites to nitrates and then nitrates to nitrogen?
Or are there two strains of anerobic bacteria that perform these two functions?

[Aquarist007]

boy nothing like an excellent on line class in microbiology--great posts Matt or Dr. Matt.

Can one assume then that the anerobic bacteria that live in the anoxic areas of the dsb and live rock perform both reduction reactions of nitrites to nitrates and then nitrates to nitrogen?
Or are there two strains of anerobic bacteria that perform these two functions?

[tmz]

Matt .

Thankyou.

I understand the carbon limitation for heteroptrophic bacteria and the likely absence of an organic carbon source in an anoxic area. Does this suggest that a deep bed with channeling organisms would be better suited to denitrification since organics would be more available?BTW Wouldn't carbon limitation make the remote unlit super deep 8 plus inches (bucket sandbed) with clean water rather useless as a denitrifying device?

You noted an inorganic carbon source , alkalinity (bi carbonate I presume ) is used by autotrophic bacteria . Do they use CO2 as well?

[Aquarist007]

<a href=showthread.php?s=&postid=14951732#post14951732 target=_blank>Originally posted</a> by tmz
Matt .

Thankyou.

I understand the carbon limitation for heteroptrophic bacteria and the likely absence of an organic carbon source in an anoxic area. Does this suggest that a deep bed with channeling organisms would be better suited to denitrification since organics would be more available?BTW Wouldn't carbon limitation make the remote unlit super deep 8 plus inches (bucket sandbed) with clean water rather useless as a denitrifying device?

You noted an inorganic carbon source , alkalinity (bi carbonate I presume ) is used by autotrophic bacteria . Do they use CO2 as well?

this is very close to what I was asking Tom but you stated it more scientifically.
I still don't have a handle on the anerobic bacteria that operate in an anoxic area===do the peform both denitrating functions(nitrites to nitrates and nitrates to nitrogen)

[JoelNB]

capn, I believe from the readings that the bacteria that convert nitrite to nitrate are aerobic autotrophs and the denitrifying bacteria are anaerobic and likely heterotrophs.

[MattL]

<a href=showthread.php?s=&postid=14951732#post14951732 target=_blank>Originally posted</a> by tmz
Matt .

Thankyou.

I understand the carbon limitation for heteroptrophic bacteria and the likely absence of an organic carbon source in an anoxic area. Does this suggest that a deep bed with channeling organisms would be better suited to denitrification since organics would be more available?Well, carbon doesn't need to be limited in an anoxic zone in a reef tank... You can have anoxic conditions and organic carbon.

However, if it is limited, then denitrification would be inhibited.

So the real question is: is organic carbon limiting in deep sand beds. I don't know. I or someone would have to do a study.
<a href=showthread.php?s=&postid=14951732#post14951732 target=_blank>Originally posted</a> by tmz
BTW Wouldn't carbon limitation make the remote unlit super deep 8 plus inches (bucket sandbed) with clean water rather useless as a denitrifying device?Again, I can't speak to whether carbon is limiting on the bottom of the bucket, but I suspect it might be, or that it might become that way over time.

Someone would have to do a study. It is not difficult to test for organic carbon, biodegradable organic carbon, and denitrifiers.
<a href=showthread.php?s=&postid=14951732#post14951732 target=_blank>Originally posted</a> by tmz
You noted an inorganic carbon source , alkalinity (bi carbonate I presume ) is used by autotrophic bacteria . Do they use CO2 as well? Yes, the two are in essence one in the same, as the carbon dioxide must be dissolved in water before it can be used by the cell.

CO2 + H2O ---> H2CO3 <==> HCO3- <==> CO3--

However, because of the pH range of our reef tanks, most of the alkalinity is as bicarbonate. This graph is for fresh water:

http://www.iav.ac.ma/agro/dss/chimiesol/images/CO3_FM.gif

As for the Calvin Cycle, which is used by autotrophs to assimilate inorganic carbon into organic carbon, I don't know which species the alkalinity is in, only that because it occurs in water, it must be as some form of alkalinity.

http://bioinfo.bact.wisc.edu/themicrobialworld/calvin.jpg

My guess is whatever the pH and the ionic strength inside the cell dictates what form the alkalinity is in.

Matt:cool:

[Aquarist007]

<a href=showthread.php?s=&postid=14951942#post14951942 target=_blank>Originally posted</a> by JoelNB
capn, I believe from the readings that the bacteria that convert nitrite to nitrate are aerobic autotrophs and the denitrifying bacteria are anaerobic and likely heterotrophs.

now I am understanding it --thanks.

[tmz]

Thank you Matt.

[MattL]

<a href=showthread.php?s=&postid=14951636#post14951636 target=_blank>Originally posted</a> by capn_hylinur
boy nothing like an excellent on line class in microbiology--great posts Matt or Dr. Matt.

Can one assume then that the anerobic bacteria that live in the anoxic areas of the dsb and live rock perform both reduction reactions of nitrites to nitrates and then nitrates to nitrogen?
Or are there two strains of anerobic bacteria that perform these two functions? Just to clarify:

The bacteria that oxidize ammonia (NH3) to nitrite (NO2) are aerobic and live in the oxic region of our tank.
The (separate) bacteria that oxidize nitrite (NO2) to nitrate (NO3) are aerobic and live in the oxic region of our tank..
The bacteria that reduce nitrate (NO3) to nitrogen gas (N2) are anaerobic and live in the anoxic region of our tank.

Here is where things get tricky. While there is only one pathway for ammonia to nitrite and nitrite to nitrate, there are many pathways for nitrate back to nitrogen gas or ammonia, depending on a variety of factors that I don't believe are yet fully understood. I drew this picture for you:

http://www.cambridgebiogreen.com/reef/nitrogen%20cycle.png

Matt:cool:

[Aquarist007]

Thanks for your excellent explanations Matt---I understand this more clearly now.

[Aquarist007]

<a href=showthread.php?s=&postid=14952593#post14952593 target=_blank>Originally posted</a> by capn_hylinur
Thanks for your excellent explanations Matt---I understand this more clearly now.

Paul must be away otherwise I am sure he would be thrilled to have a discussion with someone on such high level.:confused:

[Paul B]

Oh yes, I remember all of that :confused:

Capn, remember when you were in College?
I spent that time sleeping under a sandbag in a rice paddy.
I guess I could have brought a chemistry book with me to study the nitrogen cycle. I am not sure if they made waterproof chemistry books then and we called encyclopedia's wireless computers.
:lol:

If you want to know how to cure ich in a day or Pop Eye in a minute or get your fish to spawn or remove a tumor or get them to appear on American Idol then I am your guy.

If it is something technical you will need Matt, Randy or Whats his name? Oh yeah WK.
Those guys spent all that time taking tests so now they have to put some of that schooling to the test :D

I actually do understand that diagram, I must have made a mistake and read about it :dance: :bounce3: :dance: :bounce1: :bounce2:

[Aquarist007]

<a href=showthread.php?s=&postid=14963616#post14963616 target=_blank>Originally posted</a> by Paul B
Oh yes, I remember all of that :confused:

Capn, remember when you were in College?
I spent that time sleeping under a sandbag in a rice paddy.
I guess I could have brought a chemistry book with me to study the nitrogen cycle. I am not sure if they made waterproof chemistry books then and we called encyclopedia's wireless computers.
:lol:


Paul--that does not hold water with me as you have admitted time and time in the past that you have been and still are a voracious reader in this hobby as well as being the most experienced and knowledgeable guy I know in this hobby.

And what you and I have in common is while you were blowing up things in Nam I was in college but blowing up car engines and learning by trial and error.:eek2:
I passed on the invitation to take my Phd because I thought the stuff was crap;) and chose to go into teaching because of my love of learning and animals by getting your hands dirty.

But IMO with my lack of experience but somewhat high level of reading comprehension and retention I thought the theory that Matt presented at my request really helped explain some of the discussions on this thread.

I've been reading Calfo and Schminek's works on dsbs also. I am becoming for and more confinced that dsb's fail to to lack of maintaining layers of helpful bethnic creatures.
These are the keys for getting nitrates ect ect to the lower levels of the sand beds(the anoxic areas) where anerobic denitrfiers are
If the sand bed is too deep or the layers disturbed or made up of the wrong compositions then the transport of materials from one bethnic creature to the other is broken and the sand bed fails

Just my measly bag of concepts starting to come together.

But know amount of theory, books , college education will ever replace what I have learned from your experience on here. You are RC's shock and awe:smokin: :smokin:

BTW
My daughter just received here lieutenant stripes and starts her posting in Kingston.

[papajojo]

short term deep sand beds will act as sponges. Eventually because of one thing or another or lack there of they will reach their max. Then slowly but surely they will leach. left undisturbed lots of nasties get worse and worse till they reach catastrophic levels. so long term: 2-4 inch with varying sized media would facilitate transfer. should shallow sand beds be left undisturbed or should they be stirred or vaccumed often?

[Paul B]

Capn, I am very proud of your daughter and I don't even know her. That is the most important and honorable thing a person could do for their country and for themselves. Thank her for me.

I was in college but blowing up car engines and learning by trial and error.

I also blew up plenty of engines before, during and after the war. I even blew up a helocopter engine, unfortunately, I was flying in it at the time. :(
I was a mechanic for GM which is probably the reason they posted a 7 billion loss this quarter :D No one has ever touched my car or boat and no one ever will.

As for benthic creatures in a DSB, they will undoubtable stop multiplying, stop channeling water, and stop appearing on American Idol in a few years.
Unless organisms are added from the sea, these things will slowly stop working, but what do I know?
I diden't take "Benthic Organisms 101" But then the phds that did, do not have old reef tanks.
Yes I know Schmeck has a phd and he started in the hobby the same time as I did but He does not have an old tank either.
I guess they did not let you have a tank in college. :lol:

I have to go to Brooklyn now, lucky me :mad:
Have a great day

[Aquarist007]

<a href=showthread.php?s=&postid=14967518#post14967518 target=_blank>Originally posted</a> by Paul B
Capn, I am very proud of your daughter and I don't even know her. That is the most important and honorable thing a person could do for their country and for themselves. Thank her for me.



I also blew up plenty of engines before, during and after the war. I even blew up a helocopter engine, unfortunately, I was flying in it at the time. :(
I was a mechanic for GM which is probably the reason they posted a 7 billion loss this quarter :D No one has ever touched my car or boat and no one ever will.

As for benthic creatures in a DSB, they will undoubtable stop multiplying, stop channeling water, and stop appearing on American Idol in a few years.
Unless organisms are added from the sea, these things will slowly stop working, but what do I know?
I diden't take "Benthic Organisms 101" But then the phds that did, do not have old reef tanks.
Yes I know Schmeck has a phd and he started in the hobby the same time as I did but He does not have an old tank either.
I guess they did not let you have a tank in college. :lol:

I have to go to Brooklyn now, lucky me :mad:
Have a great day

thank you Paul--we are very proud of our daughter too.

Paul---with all your expertise did you ever blow up a deep sand bed:D I'll bet you tried to blow up the Water Keeper:lol:

[wayne in norway]

Anecdotally, and as a sand bed user my nitrates did not go to zero until I started dosing carbon. Then, after some weeks they dropped to zero and stayed there. Recently I have been trying to shift cyano and have backed off dosing C and have really gone to work with P remover, and my nitrates have gone back up to trace levels. I don't know if it's the lack of carbon or the lack of cynaobacteria to absorb nitrates that's causing this but I'm sure it'll be gone in a few days.

Cap'n, why so sure that benthic creatures have much to do with it rather than advective water flow? Huettel demonstrated what advection will do (messing around with flakes of acrylic to see how deep, quickly they buried in a sand bed), and that looks a lot more like what's going on in my sump. The worms are there, but as a method of getting nitrates down deep, I don't buy it. They might well churn up the sand and stop it forming hardgrounds tho'.

[Aquarist007]

<a href=showthread.php?s=&postid=14967594#post14967594 target=_blank>Originally posted</a> by wayne in norway
Anecdotally, and as a sand bed user my nitrates did not go to zero until I started dosing carbon. Then, after some weeks they dropped to zero and stayed there. Recently I have been trying to shift cyano and have backed off dosing C and have really gone to work with P remover, and my nitrates have gone back up to trace levels. I don't know if it's the lack of carbon or the lack of cynaobacteria to absorb nitrates that's causing this but I'm sure it'll be gone in a few days.

Cap'n, why so sure that benthic creatures have much to do with it rather than advective water flow? Huettel demonstrated what advection will do (messing around with flakes of acrylic to see how deep, quickly they buried in a sand bed), and that looks a lot more like what's going on in my sump. The worms are there, but as a method of getting nitrates down deep, I don't buy it. They might well churn up the sand and stop it forming hardgrounds tho'.

Hi from Norway Wayne and thanks for posting
I know little about advective water flow theory--perhaps you could post a laymans interpretation :)

What I posted was in reference to this article:

http://reefkeeping.com/issues/2003-06/rs/feature/index.php
by Ron Shimek

"The key to the success of such a sand bed community is water movement between the sediment grains. I mentioned above that it is essentially impossible for waves or water currents to move water in sediments. However, there is an exceptionally useful method of generating slow and even water movement through sediments. This water movement is caused by the motion of the animals in the upper inch or so of sand, particularly in those vertically-oriented tube worms such as Phyllochaetopterus, but also by all other animals moving in the upper sediment layers. The amount of water moved by one worm is quite small, on the order of a few fractions of a milliliter per day to a couple of milliliters per hour, but the cumulative total of all the water moved by all the animals in the sand bed is quite considerable. It is enough to push water into and through the sediments. "

[tmz]

<a href=showthread.php?s=&postid=14967053#post14967053 target=_blank>Originally posted</a> by papajojo
short term deep sand beds will act as sponges. Eventually because of one thing or another or lack there of they will reach their max. Then slowly but surely they will leach. left undisturbed lots of nasties get worse and worse till they reach catastrophic levels. so long term: 2-4 inch with varying sized media would facilitate transfer. should shallow sand beds be left undisturbed or should they be stirred or vaccumed often? :) In my opiion, there is no reason to beleive sand beds will leach anything or reach a so called max. They provide surface area for bacteria primarily.They're not absorbtive except perhaps for some precipitants. They do require some stirring and/or vacuuming from time to time.

[Aquarist007]

<a href=showthread.php?s=&postid=14968270#post14968270 target=_blank>Originally posted</a> by tmz
:) In my opiion, there is no reason to beleive sand beds will leach anything or reach a so called max. They provide surface area for bacteria primarily.They're not absorbtive except perhaps for some precipitants. They do require some stirring and/or vacuuming from time to time.

I agree with you Tom--if you follow the reverse food chain in the sand bed. Carbon based materials and others are consumed at each level and excreted along with co2. The creature lower in the food chain and sand bed consumes the excrement and repeats the process. At each point the original mass has decreased. Leaving the final mass for the anerobic area in the anoxic area of the sand bed. If you agree with this model (Shimek's) then if you take care of the upper layer of the sand bed and the creatures in it then you are not going to get the build up or leaching of materials to lower leve--back to the orginal post on this great thread---IMO this is major reason why deep sand beds fail---when the reefer does not actively take care of the health of that very important first layer in the substrate.

[Paul B]

They do require some stirring and/or vacuuming from time to time.

I agree with Tom, these things do require some maintenance just like everything else in life.

Hey Capn, it was a very productive day, I went to Brooklyn to do a job, it is 20 miles and took me exactly 2 hours to get there and 25 minutes to park.
I made $120.00 in 2 hours and got a ticket on my way home which coincidentially cost $120.00.
I just love NY :lol:

[Aquarist007]

<a href=showthread.php?s=&postid=14969463#post14969463 target=_blank>Originally posted</a> by Paul B
I agree with Tom, these things do require some maintenance just like everything else in life.

Hey Capn, it was a very productive day, I went to Brooklyn to do a job, it is 20 miles and took me exactly 2 hours to get there and 25 minutes to park.
I made $120.00 in 2 hours and got a ticket on my way home which coincidentially cost $120.00.
I just love NY :lol:

"green acres is the place to be" "manning a shrimp boat is the life for me--ocean speading out so far a wide skip Manhatten just give that the deep blue sea"

lyrics by eddie arnold gump:lol: :mixed: :eek2:

BTW why are you agreeing with Tom--I am the one that said it after staying up all night do extensive reserach;) just so I could stay in the same thread with you guys
boy its never good enough is it:lol: :rollface: :lol:

[Agu]

I'm a little late to this thread but I've read the whole thing.

Comments early on in this thread ...... not picking on you Paul, it was brought up several times.

I never believed the concept that "critters" in a DSB burrow under the sand to let in water to be treated. All "critters" need oxygen to live and none of them are going to burrow into a bed with no oxygen, it just aint going to happen.

I have a ten gallon with no mechanical filtration whatsoever and for the first five years it had a DSB. The only nuisance algae I had was a little on the glass, and most of it was coralline algae. I attributed it to my great skills but the truth is that I had a couple of Capitellid Worms (http://www.csc.noaa.gov/benthic/resources/species/species12.htm) cleaning my DSB.

Further Reading (http://www.pwsrcac.org/docs/d0016500.pdf)

[Aquarist007]

<a href=showthread.php?s=&postid=14970519#post14970519 target=_blank>Originally posted</a> by Agu
I'm a little late to this thread but I've read the whole thing.

Comments early on in this thread ...... not picking on you Paul, it was brought up several times.



I have a ten gallon with no mechanical filtration whatsoever and for the first five years it had a DSB. The only nuisance algae I had was a little on the glass, and most of it was coralline algae. I attributed it to my great skills but the truth is that I had a couple of Capitellid Worms (http://www.csc.noaa.gov/benthic/resources/species/species12.htm) cleaning my DSB.

Further Reading (http://www.pwsrcac.org/docs/d0016500.pdf)

good readings --thanks Agu
So are you a believer of Shimek's work and the importance of the role of micro organisms in each level of the substrate?

[Agu]

<a href=showthread.php?s=&postid=14970806#post14970806 target=_blank>Originally posted</a> by capn_hylinur
good readings --thanks Agu
So are you a believer of Shimek's work and the importance of the role of micro organisms in each level of the substrate?

NO, ......the powerhead kept pushing substrate to the back of the tank and I just kept adding heavier substrate until it stayed in place. By the time it settled in there was a DSB in the tank. :o

And I don't know where the worms came from either .......... but I do believe they are a factor in the ease of maintenance of that tank. They clean/stir the sandbed for me.

[Paul B]

Capn, Tom seems like a nice guy so I figured I would agree with him.



Quote
"I attributed it to my great skills but the truth is that I had a couple of Capitellid Worms cleaning my DSB."

AGU, I also attribute it to your great skills.
So Capn, if you want to keep your DSB running for at least 5 years you may need to add Capitellid worms.


Or of course let AGU take care of yopur tank :D

not picking on you Paul, it was brought up several times.

Oh go ahead and pick on me, I don't mind, my wife does it all the time :p

[Aquarist007]

<a href=showthread.php?s=&postid=14971363#post14971363 target=_blank>Originally posted</a> by Paul B
Capn, Tom seems like a nice guy so I figured I would agree with him.



Quote
"I attributed it to my great skills but the truth is that I had a couple of Capitellid Worms cleaning my DSB."

AGU, I also attribute it to your great skills.
So Capn, if you want to keep your DSB running for at least 5 years you may need to add Capitellid worms.


Or of course let AGU take care of yopur tank :D

Oh go ahead and pick on me, I don't mind, my wife does it all the time :p

I just posted on a thread with a gentleman named Bill. He has been in salt water for 37 years---wow that is getting close to you--there are actually two of you---you both got together you might be a match for the water keeper.

I'll stick with the bristle worms thanks---I think I saw pictures along time of go of one of those worms being caught--it was 5 feet long streched out.:eek2:

Agu--how deep a sand bed did you have to support them. If I had one of them in my tank the substrate would be heaving like phosphane in a reactor:lol:

[Agu]

At the time the DSB was 3" in front and 4" in back. But realize this is only a 10 gallon tank and it supported two worms that were close to mature size.

http://reefcentral.com/gallery/data/500/2DSCN3052.jpg

[DennisRB]

This is an interesting discussion. I was thinking about sand beds in a bucket and I wondered if a deep bucket full of sand would not be very efficient use of the available volume. I wondered if it would be more efficient to fill the bucket with a multiple layers of sand separated by plenum like areas which differed from a normal plenum in that you would encourage flow though them. So instead of having 20" of sand you could have 4 layers of 4" thick sand separated by 1" plenums with flow.

Since only the first few inches are supposedly doing all the denitrification you could increase the productivity of the bucket by many times with this method. I wondered how deep each layer would have to be which is why I was going to use 4", but going by this it may only need to be 1". So with multiple 1" layers you could increase the surface area by over 10 times in a 20" deep bucket.

I here people using the term UDSB, for upside down sand bed. What is this all about? My multiple layer sand bed bucket idea will use upside down and right way up sand beds to reduce the amount of plenums needed by putting a UDSB under a normal sandbed, separated by a sheet of plastic. I will draw a pic later.

[Aquarist007]

<a href=showthread.php?s=&postid=14972540#post14972540 target=_blank>Originally posted</a> by DennisRB
This is an interesting discussion. I was thinking about sand beds in a bucket and I wondered if a deep bucket full of sand would not be very efficient use of the available volume. I wondered if it would be more efficient to fill the bucket with a multiple layers of sand separated by plenum like areas which differed from a normal plenum in that you would encourage flow though them. So instead of having 20" of sand you could have 4 layers of 4" thick sand separated by 1" plenums with flow.

Since only the first few inches are supposedly doing all the denitrification you could increase the productivity of the bucket by many times with this method. I wondered how deep each layer would have to be which is why I was going to use 4", but going by this it may only need to be 1". So with multiple 1" layers you could increase the surface area by over 10 times in a 20" deep bucket.

here is an excellent thread on a deep sand bed in a bucket:

http://www.reefcentral.com/forums/showthread.php?threadid=595109&highlight=calfo+sand+bed+bucket

I here people using the term UDSB, for upside down sand bed. What is this all about? My multiple layer sand bed bucket idea will use upside down and right way up sand beds to reduce the amount of plenums needed by putting a UDSB under a normal sandbed, separated by a sheet of plastic. I will draw a pic later.

[tmz]

Thanks Paul,

I'll take it as high praise from a fellow Long Islander if you count Queens.

BTW while I did the college thing , I worked too and then volunteered for the military. Chose not to do OCS but enlisted for Military Intelligence, got out after 3 years as a buck sergeant but after basic training it was most mostly civilian clothes. The Russian invasion of Czechoslovakia in 1968 got me sent to Berlin when there was still a wall instead of South East Asia . I didn't complain. Out of the army and it was work, kids, two jobs back to school for a masters on the Gi bill and on and on. Never had the time or funds for reefing until I retired 7 years ago but I'll catch up with you.

I like Buffalo now but do miss the fishing on Long Island.

[tmz]

Nice photos of those worms Agu. Thanks.

Dennis RB.

Some folks like the deep bucket sand bed. I think it is a flawed design.While I think denitrification can happen in deep anoxic substrate areas ,the heterotrophic bacteria there need organic carbon to thrive.,;not just water and nitrate. The deep bucket design relies on fast water movement of preferably prefiltered water moving quickly across the relatively surface area of the bucket. I don't think much carbon will get down into the depths unless perhaps if you are dosing something like ethanol and then in a bed with no channeling from live organisms you might get a hydrogen sulfide problem. I think deep sand beds are fine nitrifiers and denitrifiers if they are kept alive and maintained. They also make great habitat for much benthic fauna and are needed by certain fish and other critters you may choose to keep. I do not think deep sterile beds do very much.

[DennisRB]

As far as I know, people just fill the bucket up with sand. The end result is a large volume of sand and not so much surface area. According to this thread the surface area is more important, hence my idea of multiple layers of thinner sand.

[tmz]

Yes but you need to insure you have anoxic areas even if they are relatively shallow and a means for organic carbon to reach them as well as nitrate. Considerations about flow, media size , and the amount of DOM in the water sourced to the bucket. Good luck with the project . Let us know how it works out.

[DennisRB]

According to this thread 1" is all that is needed for anoxic zones. But my origianl plans were for 4" layers. I don't think carbon is a worry. I am a fan of sugar dosing anyhow.

I don't see people recommending light, living creatures and detritus build up in a coil denitrator for it to work. Coil denitrators etc work fine without carbon dosing so why would that be any different to a clean sand bed?

Going by what is being claimed in this thread, this would make a remote bucket sand bed 5 times as effective as there is now 5 times more surface area, but the layers are still deep enough for denitrification.

http://i251.photobucket.com/albums/gg294/2JZR31/Multilayersandbedbucket.jpg

[wayne in norway]

Cap'n - I am in a different time zone, and much has happened in this thread. My summary would be that Ron is dead wrong, and the reality is the reverse of his position. Read this reference, or at least the abstract to get the gist of it....
http://www.aslo.org/lo/toc/vol_50/issue_3/0779.pdf
and then plough thro' the guys homesite
http://ocean.fsu.edu/faculty/huettel/Huettel_page/index_Huettel080920.html for lots of other useful things to think about.
I was initially intrigued by the ability of advection on a sand bed to work in neutral density acrylic flakes 2 centimetres plus in only a few hours using a water velocity of 10cms a second - easily attained dsb in a bucket? it's the water velovity over my sand bed in my sump.

Dennis - I tihnk sand bed depth is very important , as much as surface area. If we take a sand bed, and put no water flow over it the only things moving oxygen, nitrate, whatever in and out are diffusion (very weak) and possibly living things. Thus you will go from a zone of high oxygen saturation to one of low (or no) oxygen saturation very quickly. If we then plumb in water flow, we introduce advective flow, and lots of it thro' the sand bed. Now it will take us far longer to get from the highly oxygenated surface layer to a lower oxygen zone, and again a lot more depth to go from low to no oxygen. The surface area is the same, but the volume of the top two layers ( high oxygen and lowered oxygen) is greatly increased. Nitrate reduction to nitrate takes place (I believe) in the low oxygen zone, not the entirely anoxic, so maximising this volume is, for us, good.
The 1 inch depth to anoxia is entirely dependant on a combination of grain size and water flow above i.m.o. Increases in both increase the depth. What dies that tell us about mud and 'rooted' algae?

Finally I have never thought of my dsb as either a black hole or finite. Didn't Charles Delbeek monitor some nutrient levels in a dsb or plenum thro' time and find seasonal variation. Either way, it wasn't as a one way street.

[Paul B]

Tom thats great, I am also from Queens and was a Buck Sgt.
I knew there was a reason I liked you.

[DennisRB]

Wayne, you would obviously want slow flow through the chambers.

[wayne in norway]

I can see what you're describing. But it strikes me as very complicated compared to a single layer with a vigorous flow over the top a la 'dsb in a bucket'.

[DennisRB]

It might be more complicated than a normal bucket, but still simple enough to make. At least it will be an effective use of the total volume of sand unlike most buckets. My drawing was an extreme example with 5 layers to take advantage of the supposed thin layers of substrate this thread is advocating, you could just do 2 layers if you wanted which would not be much harder than making a single plenum with a water feed pipe.

[wayne in norway]

But if the flow is vigorous then you are making use of the sand volume, or at least more of it. Also the upside of the bucket is the higher the velocity, the more often the bucket 'sees' the tank water. For what you propose the water velocity would need to be far lower and so it would see the tank water less often. Also you aregoing to have to be very careful with regulating flow - too little and not much will get done, too much and you'll just put all the sand in an aerobic state. A buckets simple - the only limit is the sand being washed out.

[tmz]

I don't see people recommending light, living creatures and detritus build up in a coil denitrator for it to work. Coil denitrators etc work fine without carbon dosing so why would that be any different to a clean sand bed? posted byDennis RB

A coil denitrator wouldn't work if the coil was filled with sand which would obstruct the movement of the water and the material in it.


Advective flow is what moves water up and down through a sand bed along with dissolved organics,inorganic nutrients and particulate matter. Some diffusion also occurs.

Advection occurs due to a variation in water pressure as the flowing water encounters obstacles at the surface even as fine as a sand grain . Rocks and other obstacles in the flow can enhance it causing an upwelling. For example, in an illlustration in"The Reef Aquarium 3",Sprung and Delbeek, cite a model wherein advection over the sand bed moves the water down into the bed by only about 4 cm. When a 10cm rock is place in the flow , an upwelling occurs in the area of the rock which pulls the water down as much as 10cm.

So, whatever design you use it's about moving water and organic( for a carbon source) as well as inorganic nutrient matter and doing so at a rate strong enough to move the organic matter to the area where heterotrophic bacteria thrive while slow enough to ensure that an anoxic area is maintained.

[redtop03]

<a href=showthread.php?s=&postid=14627525#post14627525 target=_blank>Originally posted</a> by Paul B
Capn, I think you are correct, it's the guys that got the bonus checks.
I am submitting this picture of my gobi to the government. I may have to sell his bottle home to make ends meet causing him to be homeless. Poor little guy.
http://i258.photobucket.com/albums/hh270/urchsearch/Gobieggs014.jpg

Paul B,your aquascape is unique(at least to the aquarium world,probably looks natural where you dive though),but I like it :)

If they take his home,let me know,I'll see if I can send him a wine bottle,you may hafta help him with the Wine(don't want to make a homeless wino out of him) ;)

[Paul B]

Willie, "unique" is one of the nicer terms I have heard to describe my aquascaping. Some people describe it with some human excriment terms.

:lol:
http://reefcentral.com/gallery/data/500/13094copy_of_1317.JPG

[tmz]

<a href=showthread.php?s=&postid=14991728#post14991728 target=_blank>Originally posted</a> by Paul B
Willie, "unique" is one of the nicer terms I have heard to describe my aquascaping. Some people describe it with some human excriment terms.

:lol:
http://reefcentral.com/gallery/data/500/13094copy_of_1317.JPG :lol: Well, much of what we think we know about maintaining healthy aquarium water comes from the waste treatment industry. So your description might be a good thing.

Seriously, I do love the look of your tank; reminds me of fishing in Jamaica Bay. :lol:

[Paul B]

Tom, some of the stuff in my tank came from jamaica Bay but most of it is from the Sound :D

Except for the majority of rocks of course, I collected those in the Caribbean and Hawaii :rolleyes:

[tmz]

Where did the bottle come from?

[Paul B]

Where did the bottle come from?

There are a lot of bottles in there, maybe 10. The majority of them came from the Long Island Sound. There is a lot of history in the Sound and many of my dives were off Huckelberry Island between Queens and the Bronx. It is a tiny Island only about one or two hunderd yards long but during Prohibition it was a big party place. They had wild gin parties there and when they used to see the police coming, they would throw the boot leg Gin in the water around the Island. In the seventees almost no one dove, but I did, so we picked up a lot of old bottles.

Some of the bottles are new, I just broke them, and added some cement to age them.

This picture was taken right near Huckelberry Island, it is Execution Lighthouse which is also full of history. It was commissioned by George Washington and was a great place for artifacts. We found some round bottomed bottles here which were used for ballast in old sailing ships. Those ships had no weighted keel like modern sailboats and weights needed to be added as ballast to sail them and counter balance the weight of the sails. When the ships took on cargo to bring back to England, the ballast would be thrown overboard or left on shore.http://reefcentral.com/gallery/data/500/13094Me_in_wet_suit.JPG

The bottles after a few years in my tank, this was a new beer bottle

http://i258.photobucket.com/albums/hh270/urchsearch/Redalgae017.jpg

[redtop03]

Paul B,
regardless of what we think about it,you like it and your critters seem very pleased with it....thats all that matters anyway....if I can't say something positive about something,I usually keep my mouth shut....a lot less arguing that way. ;)

what do you do for the sharp edges on the bottles when you break them,to keep the fish from getting hurt?

some of those bottles are artwork in them selves,I have considered adding a few to my tank,that gobi is just too cute in there :)

[Paul B]

The bottles that I break, I glue together again with silicone, leaving a large piece out, then I use a dremmel (and goggles) to smooth out the cut pieces. The bottle needs to be sanded first then I smear Sakrete Mortor mix on them.
This is a new perfume bottle


http://reefcentral.com/gallery/data/500/13094Copy_of_small_bottle.jpg

[redtop03]

that makes sense,a dremmel is one of the best tools ever invented,the first tank I drilled,I used a dremmel and 2 glass etching bits,took a few hours but it worked,now I use a glass hole saw and drill,15 to 20 minutes :)

as the cap'n knows,I have a tendency to stray off subject and ramble on,I'm gonna hush now about the bottles,as I've gotten us way of topic here,thank you for the info :)

[Aquarist007]

<a href=showthread.php?s=&postid=14995843#post14995843 target=_blank>Originally posted</a> by redtop03
that makes sense,a dremmel is one of the best tools ever invented,the first tank I drilled,I used a dremmel and 2 glass etching bits,took a few hours but it worked,now I use a glass hole saw and drill,15 to 20 minutes :)

as the cap'n knows,I have a tendency to stray off subject and ramble on,I'm gonna hush now about the bottles,as I've gotten us way of topic here,thank you for the info :)

one of the other reasons that Paul has mentioned previously is that these bottles could be providing an anoxic area in the tank other then a dsb and thus supporting anerobic denitrators.:cool:

[gsxunv04]

Paul B, it looks like you have some nuisance algae outbreaks, how long have you been dealing with hair algae?

[tmz]

I think I should use the vodka bottles from the dosing I'm doing. Trouble is there are too many corals and I don't have room. Oh well.

[redtop03]

<a href=showthread.php?s=&postid=14996094#post14996094 target=_blank>Originally posted</a> by capn_hylinur
one of the other reasons that Paul has mentioned previously is that these bottles could be providing an anoxic area in the tank other then a dsb and thus supporting anerobic denitrators.:cool:

cool,I missed that somehow,I guess with the water inside the bottle not being aerated as much,it could be possible :)

[redtop03]

<a href=showthread.php?s=&postid=14996371#post14996371 target=_blank>Originally posted</a> by tmz
I think I should use the vodka bottles from the dosing I'm doing. Trouble is there are too many corals and I don't have room. Oh well.

you could put it in the sump ;)

[Paul B]

Paul B, it looks like you have some nuisance algae outbreaks, how long have you been dealing with hair algae?

About 38 years


:D

It comes in cycles, sometimes I get it every few years and it goes away for a couple of years. I use a lot of NSW from the Long Island Sound with mud and all sorts of stuff I really should not put in there. The tank is an experiment and was never meant to be a showpiece.
This picture is about 15 or 20 years old, see the algae? I haven't had any hair algae in maybe four years now.
I may not get it anymose since I installed that algae trough.
http://i258.photobucket.com/albums/hh270/urchsearch/scan0005.jpg

[gsxunv04]

Gotcha! The look is very natural, I bet you have a lot of copepods and such in all of the turf.

[Aquarist007]

<a href=showthread.php?s=&postid=14996371#post14996371 target=_blank>Originally posted</a> by tmz
I think I should use the vodka bottles from the dosing I'm doing. Trouble is there are too many corals and I don't have room. Oh well.

probably just embarased to show how much vodka you are consuming:lol:

[Paul B]

Gotcha! The look is very natural, I bet you have a lot of copepods and such in all of the turf.

There is probably Lock Ness Monsters in there but I don't really have any algae now only some very short red stuff that covers everything in the Sound. I kind of like it as it does harbor a lot of life and I find it natural looking. A lot of people will not like the look of my tank because they are used to seeing sterile looking reefs. You have to make your tank the way you like it and I like mine just the way it is. :smokin:

These pictures are only about 2 months old, see the short red stuff on some of the rocks? Thats about all I get now but the hair may return some day, not on my head, but on the rocks. I don't see it as a harbinger of doom but a natural occurance which grows on every healthy reef in the world.

http://i258.photobucket.com/albums/hh270/urchsearch/Gobieggs010-1.jpg

http://i258.photobucket.com/albums/hh270/urchsearch/Gobieggs007-1.jpg

[tmz]

<a href=showthread.php?s=&postid=14997679#post14997679 target=_blank>Originally posted</a> by capn_hylinur
probably just embarased to show how much vodka you are consuming:lol: :)
You got me. I didn't say where I was dosing it. After a few shots my tanks parameters and the whole world looks better if a bit fuzzy.:lol:

[Paul B]

Did this thread have an original purpose :lol:

[Aquarist007]

<a href=showthread.php?s=&postid=14997772#post14997772 target=_blank>Originally posted</a> by Paul B
Did this thread have an original purpose :lol:

yes, but you keep hijacking it with pictures of your wine collection;)

[JoelNB]

Paul, in your second pic from 20 years ago, what is that at the bottom left? It looks like a small morph in the photo but I have one and it seems more like a fanworm that moves about.

[Paul B]

Joel, I have no Idea. Whatever it was, I don't seem to have it anymore. It almost looks like a washed out picture of a colt coral. I always have a bunch of those and I don't remember any white corals.

[wayne in norway]

On the one of the bottles you have a branching gorgonian? How does that grow for me as I have one similar, and I am a bit disappointed in how slowly it grows.

[Paul B]

That one did grow very slowly maybe an inch a year. The one above that next to that perfume bottle grew a little faster, maybe an inch and a half a year.

[Whys]

Paul, I owe you an apology. I took exception to your use of terminology, and I believe rightfully so, but now I understand that it's not your own doing. The misapplication of the terms "anoxic" and "anaerobic" has become a common place matter of convenience even among serious authors. So I'm sorry for going off on you about it.

I recently created a diagram representing the key dynamics of a DSB, using the terminology as defined by the dictionary, rather than by creative environmentalists. To be specific, "aerobic" and "anaerobic" are biological processes, not chemical states of a sandbed. Thus what you are calling the "anaerobic" layer is in fact the "anoxic" layer and what you are calling the "anoxic" layer is in fact the "hypoxic" layer. Environmentalists have intentionally redefined these terms for the purposes of their own field of study and it is these redefined terms that you, and many others, are now using. Unfortunately, it obfuscates their true meaning and confuses the conversation.

I decided to adapt my diagram so that I might contribute it for the purpose of your theory. To be clear, it is at the bottom of the hypoxic layer where beneficial anaerobic bacteria convert nitrate to nitrogen. It is within the anoxic (truly oxygen devoid) layer where harmful anaerobic bacteria convert nitrate to hydrogen sulfide. I've added to this your conjecture regarding additional anaerobic bacteria deeper within the sandbed that convert nitrogen into ammonia

I hope this will help to further the conversation. :)

http://www.4everb.com/dsb_theory.jpg