Setting up a Jumbert system

[goodreef]

In a pure Jumbert system, I need to have a plenum, 4 inches of 2-5mm grain sand, and minimum rocks touching the sand bed. I've got the first 2 points covered, but the 3rd point is really difficult!!!

From what I've researched, I'm suppose to prop up the live rocks with PVC pipes. This way, water can easily flow around the PVC pipes, and detritus are not pushed into the sandbed.

However, setting this up is a killer.

WHAT I PLAN TO DO ...

1. Using 2 inches diameter PVC pipes, I will cut each to a length of about 6 inches. I plan to have 4 inches of PVC inside the sand, and 2 inches sticking out of the sand to support the rocks.

2. For each of the 6 inches length of PVC pipes, I will drill many big holes on 4 inches length, and leave no holes on the 2 inches part. When I stick the PVC pipes into the sand later, only the portion in the sand will have holes. The top portion will not have any holes. This way, within the sandbed, water can easily diffuse into and out of the PVC pipes through the holes. However, above the sandbed, water cannot easily move in and out of the dead space inside the PVC pipes. Though this creates a permanent dead space in the PVC pipes, it also limits the accumulation of detritus inside the pipe. An added bonus is that Pods are protected inside these pipes.

3. After setting up the plenum and filling up with 2 inches of sand, I will push the PVC pipes into position. A netting is placed on top of the sand, and 2 more inches of sand is placed on top. Check to make sure that the sand level inside and outside the pipes MUST be about the same.

4. Small holes are drilled on the PVC end caps, and fitted to the TOP end of the PVC pipe. This way, pods can easily move in and out without being eaten. Also, this really limites the detritus accumulation inside the pipes.

5. Rocks are arranged on top of the PVC pipes.

6. A wave maker is used to make sure that there are no dead spots between the sandbed and the rocks.

Potential issues with the above ...

1. With this design, there will be dead spots inside the PVC pipes. Yes, water can still diffuse through the top cap of the pipe, and at the bottom of the sandbed. That's it. Anyone feel that this will be an issue later??

2. If all the 2 inches diameter PVC pipes are stand-alone and not connected to any main structure, do you think that the entire rock structure above will collapse after some time?? Afterall, 4 inches of the PVC pipe is burried inside the sandbed, and only 2 inches will be above the sand bed. Also, I assume that the pressure from the weight of the rocks will be downwards, making the overall structure even more stable?? Any engineers can help??

3. Any obvious design flaws??

Please comment. Thanks!!!

[O'Man]

When I had my plenum tank all I did was use smallish pieces of live rock to prop up the bigger pieces of live rock to prevent the sandbed from being totally sealed. It was never 100% open, but it worked.

[Conky]

You could also make an elevated "shelf" of fiberglass grating material (or eggcrate) which sits on top of the PVC pipes (or other type of risers) in order to support the rockwork. That way the rock will not be "sunk" into the sand, but merely sitting on or above it. Since live rock is rarely flat, there will be channels for water to work its way underneath. You can cover up the grating with sand so you don't see it.

In reality, as long as you're not planning on covering a substantial portion (more than 30%) of the sandbed completely with live rock, I don't think you'd have any issues. I take care of a system (3 tanks), which has been running a plenum for over 10 years, in which the rocks are sunk directly into the sand.

[Conky]

Oh yeah...and its "Jaubert", though it doesn't really matter.

[szeth13]

drill holed in the rock and insert cut pieces of plastic coat hangets, epoxy them in the rock if you want. that is what i did for my bb

[goodreef]

Thank you very much for all your kind comments!!!

Conky, I focused too much on PVC pipes, and forgot all about using eggcrate!!!

I've since modified my design to using 90% eggcart, and minimal PVC pipes!!!

[Putawaywet]

If memory serves me didn't Dr. Jaubert use a single uplift tube with an airstone in one rear corner of the tank? Something about it's purpose being to slowly diffuse a small amount of water thru the sandbed?

Some where, some place, I think I have the original Tom Frakes SeaScope article whith the Jaubert methodology. Just don't ask me where it's hiding :)

Brett

[goodreef]

I think what you describe is the ORIGINAL natural system ... I think by someone else, not Jaubert.

Here is a commentary by Julian Sprung the noted aquarist on the Jaubert system:

http://www.advancedaquarist.com/issues/sept2002/feature.htm

[Putawaywet]

Ok, no airlift tube, just airstones randomly placed. Guess my memory isn't what it used to be.

Been a while since I read info on that system. Actually, I'm curious as to what took Sprung so long to do a review. The research info on Jaubert method has been around for a good decade.

Regardless, I think it's a cool diversion from what everyone else is doing at the present.

Best of luck
Brett

[Fredfish]

The jaubert system has pretty much been shown not to do anything more than a regular sand bed. See Eric Borneman's article in this month's RK mag.

Fred

[goodreef]

<a href=showthread.php?s=&postid=9191547#post9191547 target=_blank>Originally posted</a> by Fredfish
The jaubert system has pretty much been shown not to do anything more than a regular sand bed. See Eric Borneman's article in this month's RK mag.

Fred

Great article!!!

However, it's main argument is that the Jaubert System does not provide enough calcium and alkalinity to the tank, as initially suggested as Jaubert. I agree on this point.

It DOES NOT mention or discuss about the "filtering" ability of the Jaubert System, which is the main benefit that I'm looking for.

My personal experience is ... no algae growth on glass tank with Jaubert System (about 3 years). Once I shifted to a new bare bottom setup, green algae started to grow significantly on the glass tank throughout the life of the setup (about 2 years)!!! So, from first-hand experience, I do NOT think that the Jaubert System is just a regular sand bed!!!

[Conky]

"I think what you describe is the ORIGINAL natural system ... I think by someone else, not Jaubert."

I believe you're referring to Dr. Eng. He advocated a very simple system employing live rock and water motion provided by airstones.

That being said, I'm sure there are literally hundreds (or more) people who tried similar things over the last century or so. There are very few NEW ideas to be had...

[Fredfish]

From the Eric's article: "Over the years I kept over a dozen Jaubert systems with a plenum, but I eventually arrived at the anecdotal conclusion that the plenum space had no real function. This conclusion was later confirmed by Toonen (2005a, 2005b) and Delbeek (2002)"

Fred

[billsreef]

I've run both plenum's and DSB's without plenum's. They both work well. That said, I wouldn't bother with the hassle of setting up a plenum since it doesn't gain any advantages over simply putting a DSB straight on the bottom of the tank ;)

[goodreef]

According to Julian Sprung, both with or without plenum works ... however, the denutrification process in both are different.

With plenum = Jaubert system = sand grain about 2-3mm + 4 inches.

Without plenum = DSB = sand grain < 2mm + > 4 inches, and the deeper the better!!!

I really think that BOTH methods works well, but I advice against mixing up both systems. Many people think that the denutrification process is the same, and thus, the sandbed becomes less effective.

[Conky]

Referring back to Rob Toonen's study, I don't believe or grain size or depth had much bearing on the efficacy of DSBs or plenums. I think large grain <1in was less effective. That was over 2 years ago...so my memory could be faulty. I'll try to find my notes.

goodreef...how is denitrification different between the two setups? No offense, but I don't understand. If Julian argues for +4 inches on both...I don't get it. The only difference is recommended grain sizes. Basically, you're just providing more anaerobic intersitial spaces with the DSB and utilizing the "dead space" under the plenum for the same purpose. I don't even know if this is accurate...no offense to Julian Sprung. Mr. Borneman argues that the plenum is just dead space.

I'm not trying to argue with you...just don't understand what you mean by "denitrification process in both are different".

[goodreef]

Very good question!!! Same question that many reefers are asking … including myself. My info is purely from Julian Sprung’s latest volume 3 installment of his book.

Julian also referred to Rob Toonen's study 2 times, and agreed that all the different system achieved filtration in the water ABOVE the sandbed. However, Julian feels that things are different WITHIN the sandbed. Thus, he mentioned that the denitrification process in both are different.

From Julian’s observation, he also disagreed that the plenum has no function. 2 functions mentioned are:
1. reducing the chances of hydrogen sulphite development in the sand bed.
2. helping to breakdown detritus within the sand bed. On this point, he is not sure if the reduced detritus is due to the plenum, or the fact that the Jaubert System has less rock on the sandbed.

Please note that Julian did not say that the plenum helps with filtration. This view is consistent with Rob’s observation.

Additionally, Rob Toonen's findings are for 6 months, where Julian Sprung’s observation are in terms of years. I don’t think 6 months is long enough to observe the differenced in the accumulation of detritus.

Please note that Julian AGREES with Rob regarding the filtering of water ABOVE the sandbed. And Rob did not really study the situation BELOW the sandbed, where Julian made many of his observations & assumptions.

In all honesty, I do not think anyone has the answer. However, all we can say is that it works well as a filtration method.

[Conky]

Agreed on the length of Toonen's study...6mos is really short in the grand scheme of things. Are you referring to vol 3 of "The Reef Aquarium (Delbeek and Sprung)? If so, I haven't gotten my hands on it yet...sounds like I need to get hold of it.

Did he (mr. Sprung) actually do a quantitative study on this, or is it all based on experiences with tanks he has set up? If accumulation of detritus was lower in plenum tanks, wouldn't that possibly suggest that plenums were actually more suited to supporting detritivorous infauna? In essence, wouldn't that mean plenums work better in the long run? Or was he just saying that all of the detritus settled unerneath the plenum instead of at the bottom layer of the sandbed?

As far as Jaubert systems having less rock on the sandbed...I don't think that's really true. If it is...aren't we just introducing another variable into the equation? I think a lot of (modern) plenum systems look identical to standard DSBs in regards to rock covering.

I'd really be interested in someone doing a study that didn't bring live rock into the equation. Perhaps that's where the denitrification is taking place...Dr. Shimek suggested that in the past.

Personally, I think it would have made more sense (i.e. eliminated more variables) if waste had been introduced via ammonium chloride as well. I think we'd get a "cleaner" view of what is going on regarding denitrification. Obviously, it wouldn't be a good representative of what is going on in our tanks, but it would probably give a better view at the chemical level.

FWIW, I manage a 4000 gallon (split into 3 displays) reef that is 10 years old, and is built up on a plenum. NO3 (not NO3-N) runs around 4ppm (via spectrometer) and phosphates range between 0.01 and 0.03 ppm. A newer tank (5000 gallons, 2 years old) also employs a plenum and has similar readings. That being said, I probably would never include a plenum in a home tank, as it is probably just a waste of space.

[paulsilver]

so the question is, with a 210 g reef, and a 75 g refugium attached via the sump, what sort of sand bed would be recommended?

I was leaning toward a Jaubert method, with plenum, but then was talked out of the plenum, then back to it...

So, to plenum or not to plenum, that is the question...

Note that once the refugium is established, I am thinking of adding a 210 fish only to the system... thoughts on this as well would be welcomed... re: sand beds, nutrients, etc.

[goodreef]

Conky, yes, I was referring to The Reef Aquarium (Delbeek and Sprung) vol 3. The cost put me off initially, but after reading the whole book, it is a MUST HAVE for any serious reefer!!! Cleared up many questions for me.

Unfortunately, Sprung's book did not explain the detritus in detail ... in fact, his conclusion is based on his observations, and not through testing. Also, he also remarked that it is not conclusive, and he may be wrong.

As for rocks in Jaubert systems, the ORIGINAL Jaubert system only has minimal rocks. What you mentioned are modified Jaubert systems, which Sprung explained in detail, will cause the system to fail over a long period of time.

Paul, problem with this plenum thing is that it is still not conclusive till now ... so all the opinions and advices in the world is just that ... opinions and advices!!! Remember, even in Eric Borneman's article, the variance in the exect same setup was very significant, let alone what we setup in our home tanks!!! Regardless of what we choose, we will not be very far from the truth ... both systems are only very marginally different from each other. I doubt you will go wrong with either!!!

For me, I'm still going with a plenum in my new system, as I had great success with it in my last setup!!!

[Conky]

"As for rocks in Jaubert systems, the ORIGINAL Jaubert system only has minimal rocks. What you mentioned are modified Jaubert systems, which Sprung explained in detail, will cause the system to fail over a long period of time."

Why? I'm very curious....guess I better get the book. Our 4000 gallon reef is such a "modified Jaubert" system and has been operating for over 10 (maybe that's not a "long" time) years without any major issues. NO3 < 4 mg/L, PO4 <0.03 mg/L, Ca and Alk maintained at reasonable levels with kalkwasser additions. Why is it destined to fail? It's dominated by soft corals (mostly Sinularia, Capnella (maybe), Sarcophyton, Lobophytum, Zoanthids, Corallimorphs), but has two laminar Hydnophora that are well over 2 ft across as well as a couple of Acropora and some larger-polyped species (Platygyra, Physogyra, Plerogyra, Scolymia, Turbinaria, Euphyllia, Caulastrea, etc.)

How long is a "long" period of time, I wonder?

Not mocking you...I promise. But that's a big statement from someone who has never examined quantitative data. Lots of people have blame lots of "techniques" for tank crashes over the years. In reality, I think we're all just rolling the dice...

Why do i feel like I've just DOOMED myself for a catastrophe? Gotta go find some wood to knock on...

[goodreef]

From what I gather from the book, it is important in the Jaubert systems to have water diffusion in the sand beds. If too much rocks are on the sandbed, water hitting the rocks will push detrius into the sand bed, thus greatly reducing the space between the grains of sand. Similar to "clamping" effects on sand bed. Once water diffusion in the sand bed drops, hydrogen sulphate forms, and things goes down from there!!

But if the rocks are minimal, or if they are lifted off the sand bed, the sand bed will remain relatively free from "blockages" and water diffusion and its filtration effects will be optimised.

[goodreef]

To quote Delbeek & Sprung in The Reef Aquarium, pg 343-344

"In a properly established Jaubert system aquarium there is much less rock, leaving wide expanses of the bottom uncovered. The reason for this is twofold. First, since the biological filtration occurs within the gravel bed, the live rock is not needed for biological filtration. One can set up a Jaubert system with no rock at all. Its purpose is just for decoration and the introduction of biodiversity. The second reason for the paucity of rock is that the surface of the gravel bed should be left uncovered as much as possible. This allows unrestricted exchange of oxygen and other dissolved substances, and minimizes advection of detritus into the substrata."