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-   -   Vodka dosing and alkalinity questions (http://www.reefcentral.com/forums/showthread.php?t=2660357)

EnderG60 12/04/2017 08:04 AM

Vodka dosing and alkalinity questions
 
So I started Vodka dosing in an effort to reduce my phosphates without needing so much GFO.

I remember reading that alkalinity over 9 was not recommended as people were seeing SPS with burned tips.

Prior to vodka I had always kept my alk pretty high (in the 10-12 range) since my LPS seemed to like it and the SPS didnt mind. When I tried to do the same while dosing vodka I started seeing some burned tips and tissue loss.

So why the difference with the vodka?

bertoni 12/04/2017 08:19 PM

No one has any particularly credible theory as to what's happening. Some people think that the faster growth is causing some sort of problem, as higher alkalinity makes calcification easier. I think I remember other theories as well, but I don't think any of them have much in the way of data to support them.

EnderG60 12/05/2017 12:00 PM

I have heard of regular SPS tanks having that issue, but Im more curious why I only started having the issue when I began vodka dosing.

tmz 12/05/2017 12:15 PM

Hard to say. Vodka is ethanol and water. The ethanol goes to acetate which feeds heterotrophic bacteria that use it as a carbon source ;they also deplete other elements particularly PO4 and NO3. Both are used by corals in their growth process including their control of the growth of the skeletal matrix ; depleting them requires the coral to adjust. If deficiencies in nitrogen or phosphate occur it can throw the balance for controlled growth off; more so it seems when higher alk encourages faster calcification.

FWIW I have been dosing vodka and vinegar for over 8 years in a a heavily fed mixed reef system with a majority of sps. PO4 holds between .02 to .04 ppm with NO3 under 1ppm. alk in the 8 to 10 dkh range doesn't occasion burnt tips or other stn in my case.

Once in a while a very small of sodium nitrate offsets any potential nitrogen deficiency.

mcgyvr 12/05/2017 12:20 PM

Quote:

Originally Posted by EnderG60 (Post 25294053)
I have heard of regular SPS tanks having that issue, but Im more curious why I only started having the issue when I began vodka dosing.

It just seems that with lower nutrient levels corals cannot "adapt (or tolerate)" to the higher alkalinity levels..

Now you didn't mention any specific nutrient levels of neither nitrates nor phosphates but I'd bet that the vodka is causing your nutrient levels to be lower (as it should) thus the corals cannot tolerate the higher alk without getting burnt..

I'm sure there is likely a scientific answer where one plots zooxanthellae growth rates against coral calcification rates and shows an imbalance that forms in your situation and thus the zoox cannot keep up with calcification or whatever..

JustAClownFish 12/05/2017 07:36 PM

Quote:

Originally Posted by EnderG60 (Post 25292821)
So I started Vodka dosing in an effort to reduce my phosphates without needing so much GFO.

I remember reading that alkalinity over 9 was not recommended as people were seeing SPS with burned tips.

Prior to vodka I had always kept my alk pretty high (in the 10-12 range) since my LPS seemed to like it and the SPS didnt mind. When I tried to do the same while dosing vodka I started seeing some burned tips and tissue loss.

So why the difference with the vodka?


Do you know why you're seeing burned tips with higher alk? When you dose vodka you reduce nutrients such as phosphate, which is known to inhibit calcification, so your SPS can take up more alk/ca, thus grow faster. In other words, the skeleton outgrows the soft tissue. It's just a cosmetic thing. If you don't like it keep your alk at a NSW level of 7dkh.

DesertReefT4r 12/05/2017 10:46 PM

Keep your alk at 7-8dkh when dosing vodak or you will burn your sps. I did vodka for a while and it does work but bio pellets are easier and more forgiving ime.

Daddi0 12/05/2017 11:48 PM

Quote:

Originally Posted by JustAClownFish (Post 25294495)
Do you know why you're seeing burned tips with higher alk? When you dose vodka you reduce nutrients such as phosphate, which is known to inhibit calcification, so your SPS can take up more alk/ca, thus grow faster. In other words, the skeleton outgrows the soft tissue. It's just a cosmetic thing. If you don't like it keep your alk at a NSW level of 7dkh.

Will increased food for the reef and fish help the soft tissue "keep up"

Belgian Anthias 12/06/2017 08:50 AM

Dosing carbohydrates produces protein, biomass. A part of this protein will be removed by a skimmer ( max +- 30%, http://www.baharini.eu/baharini/doku...iwitafschuimer ) most of it will be consumed by other organisms and become part of the food chain. Consumption is formation of biomass and ammonia. This ammonia will be nitrified to nitrate. Nitrification does consume alkalinity. To remove the nitrate produced carbohydrates must be dosed. A cycle is introduced from NO3 to NO3 , this cycle includes nitrification consuming alk.

At a high C:N ratio ( biopellets reactor?) no nitrate is formed as ammonia will be assimilated to produce protein. The assimilation of ammonia NH4 consumes alkalinity but only +- half of alk consumption if the same amount of ammonia was nitrified. At the downsite the very high biomass production which is +- 40 x the amount produced during nitrification of the same amount of ammonia. The cycle introduced this way is from NH4 to NH4. including the formation of a lot of biomass.
What to do with the produced biomass?
Carbon dosing is common practice in aquaculture systems. In these systems the biomass will be harvested after a period of time.

EnderG60 12/06/2017 12:52 PM

Quote:

Originally Posted by JustAClownFish (Post 25294495)
Do you know why you're seeing burned tips with higher alk? When you dose vodka you reduce nutrients such as phosphate, which is known to inhibit calcification, so your SPS can take up more alk/ca, thus grow faster. In other words, the skeleton outgrows the soft tissue. It's just a cosmetic thing. If you don't like it keep your alk at a NSW level of 7dkh.

Exactly what I was asking about, thanks!

Im finding the new balance of parameters with the vodka dosing now. My original goal was to reduce my phosphate to inhibit the algea growth. I started with my nitrates at 2-4, and phosphate at 0.3-1.2. I got to a point where my nitrates zeroed out and my phosphate was still in the 0.3-0.5 range, so I started dosing sodium nitrate.

Im now holding steady with nitrates of 2-4, and phosphate of 0.01-0.03, while dosing a 450g system with 21 ml a day of vodka which I think should be a good happy spot for a mixed reef.

So now I just need to find a new dosing balance now that I have the vodka dosing figured out. My alk intake has gone up quite a bit but never seems to go above 8. If I dose it manually it jumps for a day, I get burned tips and then its back down to 8.

I just want to make sure I understand whats happening so I dont start chasing old numbers that wont work anymore.

bertoni 12/06/2017 01:28 PM

To be very precise, the skeleton can't outgrow all the tissue of the coral, because the tissue forms the skeleton:

http://www.advancedaquarist.com/2002/4/chemistry

The "burnt tips" might be places where the tissue is very thin, in some cases, at least. Other people seem to see tissue recession and similar signs of poor coral health.

DesertReefT4r 12/06/2017 08:17 PM

Quote:

Originally Posted by Daddi0 (Post 25294721)
Will increased food for the reef and fish help the soft tissue "keep up"

If your no3 and po4 is super low yes it will. Corals need light and food for their photosynthetic algae to thrive, a major nutrient source for algae is nitrogen and phosphate. You want to keep levels low but detectable. If you system already has controlled low nutrients carbon dosing will not help any and can cause major issues.

EnderG60 12/07/2017 04:35 PM

Ok part 2. Why has the vodka dosing caused my alk dosing to nearly double?

Tripod1404 12/07/2017 05:45 PM

I nature corals grow in very low soluble nitrate and phosphate levels (almost in trace amounts) and the alkalinity of natural sea water is around 7.5dKH.

In a tank if you try to replicate the low nutrient levels (through carbon dosing and subsequent consumption of nitrate and phosphate), you need to lower alk as well.

The reason for this is not very clear. But from a very simplistic point of view. corals need Ca and Alk to built their skeletons. More alk allows more skeleton to be built. But this also requires the coral soft tissue to grow larger and produce more calcium carbonate. So in higher alk coral cells themselves need more phosphate and nitrate to grow and built CaCO3 skeleton, but they also need N and P to feed their symbiotic algae. And in lower alk, the case is the opposite.

Phosphate is also known to be a substrate that protects corals from bleaching. Now its important to consider that whitening happens first around the tips, than the parts of the coral that receive more light and eventually the whole coral will turn pale.

Tips of the corals normally receive the most light and they are the parts that grow the most. So I think what happening is a nutrient imbalance between the symbiotic algae and the coral cells. Corals and zooxanthellae form a synbiotic relationship where corals provide the nitrate and phosphate and in turn algae share some of the carbon dioxide it fixes into organic compounds with the coral. When you have high alk but low N and P, it creates a large nutrient imbalance around the tips. When N and P drops but the alk is high, both zooxanthellae and the coral cells require N and P. Since there is not enough N and P for the both, coral expels some of the zooxanthellae to reduce the demand, hence they turn pale. This is followed by the paling of the parts of the coral that receive more light. In these tissues, coral growth is slow (but there still is growth as branches get thicker over time), but since they get good light algae still need N and P. If N and P are low, coral expels them to reduce the population. Otherwise they will drain the coral cell of N and P. The last parts to get pale are the shaded regions since the N and P demand of the algae living there are the lowest.

Now the actual tip burning (tissue necrosis) happens becouse of rapid N and P drops. In this case N and P become limiting so fast that coral doesn't have time to expel the zooxanthellae. THis cause an extreme N and P starvation. This cause generation of reactive oxygen (ROS) species that kill the cells.

So why does ROS form? It is because the mechanism how photosynthesis operate. This is true for zooxanthellae, cynaboacteria or higher plants. Photosynthesis is simply a process that cannot be turned off. Higher plants have the most complex regulation over this (and regulation corals have is no where near to what higher plants have) and they try to control it by moving their leaves or moving their chloroplast, etc to achieve shading, but even then they have a tolerance limit. Chlorophyll will simply continue to harvest light energy, if there is not enough N and P to produce the enzymes (require N) and ATP (require P) to harvest and distribute this energy, that energy will be dissipated by transferring it to oxygen and water molecules. This forms the highly reactive oxygen intermediates that simply burn the cell from inside out. And this results in tissue necrosis.

So long story short; low N and P require alk to be low as well, because high alk put more demand on N and P from the corals as well. When there isnt enough N and P for both the coral and the zooxanthellae. Zooxanthellae gets kicked out.

bertoni 12/07/2017 07:11 PM

Quote:

Originally Posted by EnderG60 (Post 25296530)
Ok part 2. Why has the vodka dosing caused my alk dosing to nearly double?

That increase in consumption might be due to increased coral and coralline growth. That'd be my first guess.

bertoni 12/07/2017 07:15 PM

Quote:

Originally Posted by Tripod1404 (Post 25296591)
I nature corals grow in very low soluble nitrate and phosphate levels (almost in trace amounts) and the alkalinity of natural sea water is around 7.5dKH.

In a tank if you try to replicate the low nutrient levels (through carbon dosing and subsequent consumption of nitrate and phosphate), you need to lower alk as well.

The reason for this is not very clear. But from a very simplistic point of view
...

That's an interesting hypothesis. I hadn't thought much about ROS being an issue, but that's possible. We'd also need to know how corals control the calcification process to begin to validate this theory.

Belgian Anthias 12/17/2017 10:20 AM

Quote:

Originally Posted by EnderG60 (Post 25295261)
Exactly what I was asking about, thanks!

Im finding the new balance of parameters with the vodka dosing now. My original goal was to reduce my phosphate to inhibit the algea growth. I started with my nitrates at 2-4, and phosphate at 0.3-1.2. I got to a point where my nitrates zeroed out and my phosphate was still in the 0.3-0.5 range, so I started dosing sodium nitrate.

Im now holding steady with nitrates of 2-4, and phosphate of 0.01-0.03, while dosing a 450g system with 21 ml a day of vodka which I think should be a good happy spot for a mixed reef.

So now I just need to find a new dosing balance now that I have the vodka dosing figured out. My alk intake has gone up quite a bit but never seems to go above 8. If I dose it manually it jumps for a day, I get burned tips and then its back down to 8.

I just want to make sure I understand whats happening so I dont start chasing old numbers that wont work anymore.

21ml vodka 40% volume (915,6 gr/l) contains +- 15,14% carbon in weight or 2,91 grams C
This is enough to assimilate 0.1918 grams N (15,17gr C/1 gr N) http://www.baharini.eu/baharini/doku...:vodka_ethanol
This may produce 1.55 grams protein if enough phosphor P is available.
To be able to assimilate 0.85 gram NO3 (0.1918 N) or +- 0.5ppm ( 1700l) +- 0.08 grams PO4 is needed
The total amount of PO4 is +- 1600 x 0.03ppm = 48 mg or 0,048 grams
Taking in account that phosphate is produced constantly I am pretty sure that phosphate is the limiting factor in this tank making it very difficult for all living creatures and not only for the corals.
As only +- half of the carbon dose can be taken up immediately the stress situation may cause decay and may prevent nitrification and denitrification.
My advice is to reduce the dose at least by 1/2 or stop dosing but do this very slowly over a period of at least 10 days as not enough nitrification capacity may be available.

Belgian Anthias 12/17/2017 11:01 AM

Alk
 
Quote:

Originally Posted by EnderG60 (Post 25296530)
Ok part 2. Why has the vodka dosing caused my alk dosing to nearly double?

Dosing carbohydrates causes growt and respiration. +- 3.57 gram alk is consumed for each gram N removed from the water column. (EblingEnCo2006>http://www.baharini.eu/baharini/lib/...0216x-main.pdf)
As the produced protein must be consumed and the consummation sustains biomass, most is released as ammonia and some ureum. The carbon becomes part of the normal food chain, most is released as CO2. The ammonia is nitrified. By dosing carbohydrates a cycle is created from NO3 to NO3 which includes nitrification. Nitrification consumes alk.
At high C:N ratio the cycle is from NH4 to NH4 avoiding nitrification.

bertoni 12/17/2017 06:05 PM

Dosing vodka or vinegar will consume alkalinity for a short period of time because an organic acid is formed. As the organic acid is consumed, the alkalinity will be released. I suspect other carbon sources could produce organic acids, as well.

As nitrate is consumed, alkalinity will be released. This article discusses alkalinity in the nitrogen cycle.

http://reefkeeping.com/issues/2004-12/rhf/index.htm

The theory behind carbon dosing is that some of the biomass is exported via skimming. That's very difficult to prove or quantify, but carbon dosing does seem to work very will in many systems.

Belgian Anthias 12/18/2017 08:14 AM

I have no doubt that carbon dosing works to remove nitrate from the water column. It is also a fact that dosing carbon increases the bio-load in the system and it becomes part of the food chain. What happens when dosing is stopped for some reason?

Articles about carbon dosing do not take in account the daily overproduction of nitrate. An aquarium system can have a concentration of 10ppm nitrate and be perfectly in balance at this level, production equals consumption. What happens when in such systems carbon is dosed to lower the level?
An aquarium system that is perfectly in balance at a nitrate concentration of 2ppm and daily doses of in total 2ml/100l vodka40%. What will happen when the dosing is interrupted or stopped? Would it be possible that the same system finds its natural balance at a nitrate level of 10ppm without dosing?

Skimmers remove max +-25% of DOC and max 35% of TOC available in the water column and are very selective in removing live bacteria which is an issue worth to be researched. Most of TOC is not available for skimming as it is bentic. http://www.baharini.eu/baharini/doku...iwitafschuimer

The theory behind carbon dosing and the removal of the biomass by a skimmer stands. But only for a small amount and the removal is certainly insufficient to prevent build up of the bio-load.

Before the nitrate will be used the immediate available ammonia NH4 is taken up. The assimilation of ammonia NH4 by dosing carbohydrate consumes alk by producing CO2 using inorganic carbon from alk; Once nitrate is taken up it is transformed internally into NH3 , one must take in account the respiration. When the produced protein is consumed most is released in the water column as NH3 and is ionized to NH4. When not consumed all is released and used during decay. Ebling en Co take all this in account also the alk shift in seawater.
All this results in the fact that +- 3.57 gram alk is consumed for each gram N

Table 4. Stoichiometry for heterotrophic bacteria metabolism of 1.0 g NH4+–N with carbohydrate as supplemental carbon (EblingEnCo2006>http://www.baharini.eu/baharini/lib/...0216x-main.pdf)

Heterotrofe ammonium reductie http://www.baharini.eu/baharini/doku...onium_reductie

The work of Ebling en Co does also covers photoautotropic and autotropic ammonia reduction in ZMAS.

In zero emission marine aquaculture systems (ZMAS) for cultivating shrimp carbon dosing is common practice and is used as part of the food chain. Measures must be taken to compensate for the alk consumption due to carbon dosing. In these systems the production of nitrate ( nitrification) is prevented by the high C:N ratio. After a period of time the cultivated biomass is harvested.

bertoni 12/18/2017 02:34 PM

We've been through this many times before. Carbon dosing can be very useful. As far as what happens when the dosing is stopped, I've never read of any particularly bad results

Belgian Anthias 12/18/2017 07:29 PM

Unaswered questions.
 
Still a lot of questions about carbon dosing in marine aquaria stay unanswered. As long questions are unrequited one must continue asking them to find answers.

Is carbon dosing useful?
Nitrate is not a problem in marine aquaria. Problems occur when not enough nitrate is available as many bio-chemical processes need nitrate.
Carbon dosing has to many known caveats and to many not fully understood side effects to be useful for managing a home aquarium.
How safely stop dosing carbon should be included in any advice given for starting using it. It would be a useful advice. Starters should be warned for possible irreversible problems and how to prevent them.

What about the use in LNS or VLNS? The creation of stressed systems? Bleaching corrals?
A long list of questions can be asked which will stay unanswered.
To many question marks.

If one thus not know what happens when carbohydrates are supplemented to a closed system one should not consider using it. Everybody can follow a dosing guide but the guide will not tell a thing about the stress caused to the system and its habitants when the doses are not corresponding with the needs.
Often the advised doses are linked with the nitrate concentration and applied without any other consideration.

Carbon dosing in marine aquaria systems is to much based on assumptions for to be used safely. Nobody has a clue how much is actually removed from the system and what to do after a certain period with the cultivated biomass. Most side effects are known but are poorly investigated in marine aquaria.
Wood you feed your dog something you do not know if he can digest it? Or is the assumption he will not die from it enough to try it?

Afterwards it is difficult to proof what caused system crashes. A lot of system crashes can be linked to carbon dosing. Mostly because of insufficient nitrification capacity when dosing is interrupted or stopped . A very active system that is suddenly confronted with the new tank syndrome .

A lot of research has been done for the development of ZMAS systems depending on carbohydrate dosing on which I have documented myself , In these systems biomass may increase till 80kg/m³ without nitrate formation. How it works is fully understood. For most of the caveats there is a solution. When dosing is interrupted one has to restart with a new batch. After a known period of use the biomass is harvested and the system is restarted.

Skimmers are used to remove as much as possible TOC. Dosing carbohydrates replenishes total organic carbon ( TOC),

May the use of carbohydrate supplements in marine aquaria be advised? Not by me, not on the assumption that it ends up useful.

I use it for completing the food chain for cultivating live food in a refugium.

hkgar 12/19/2017 02:26 PM

Quote:

Originally Posted by tmz (Post 25294073)
Hard to say. Vodka is ethanol and water. The ethanol goes to acetate which feeds heterotrophic bacteria that use it as a carbon source ;they also deplete other elements particularly PO4 and NO3. Both are used by corals in their growth process including their control of the growth of the skeletal matrix ; depleting them requires the coral to adjust. If deficiencies in nitrogen or phosphate occur it can throw the balance for controlled growth off; more so it seems when higher alk encourages faster calcification.

FWIW I have been dosing vodka and vinegar for over 8 years in a a heavily fed mixed reef system with a majority of sps. PO4 holds between .02 to .04 ppm with NO3 under 1ppm. alk in the 8 to 10 dkh range doesn't occasion burnt tips or other stn in my case.

Once in a while a very small of sodium nitrate offsets any potential nitrogen deficiency.

If I remember correctly, you are dosing vinegar/vodka at 70/30? How many ml/gallon are you dosing? Thanks


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