Nitrate and the BIO filter!

[Belgian Anthias]

I do not agree. It is depleted. How would it? lol



Why would adding acetic acid or ethanol increase nitrification? How could it? You are not adding nitrogen.



It essentially drives the incorporation of nitrogen into organic matter. Sources of that N might be ammonia or nitrate. Neither process results in any depletion of alkalinity.



No. That is a totally incorrect assertion and may be the basis of our disagreement.

Ammonia to organic matter and back to ammonia has ZERO impact on alkalinity (nitrogen is in the same oxidation state in ammonia and in organics such as a protein), and that result does not depend on whether the ammonia was converted into nitrate before incorporation into organic matter or not. if you convert it first into nitrate, you lose alkalinity, and then you get that same alkalinity back again if you convert it into either ammonia or organic matter.

NO3 ( + phosphate +?) + carbohydrates = protein Protein + consumption= biomass + ammonia ammonia + seawater = NH4+ NH3 NH4 + nitrification ( alkalinity consumption) = NO3 NO3 + carbohydrates = an ongoing chain of biomass + ammonia production which includes the nitrification process. Biomass grows and stays in the system!
At high C:N ratio the chain will be from NH4 to NH4 without nitrificition because no nitrate will be formed as all ammonia will be assimlated. The assimilation of NH4 consumes alkalinity! The produced biomass stays in the system!
The produced protein must be consumed or removed to have any effect on the nitrogen and phosphate concentration in the water column. The effect is limited to the increasing biomass and what may be removed by the skimmer. All will be recycled when the cultivated biomass dies off. At the end of the food chain this will be the fish which feeds on the organisms fed by the produced protein. To have no effect on alkalinity on must wait till the fish is decomposed and mineralized.!? The protein removed by the skimmer = alkalinity loss.!?

 

[Belgian Anthias]

As heterothropic ammonia reduction prevents nitrification there will be insufficient nitrification and denitrification capacity in the system in comparison to the present biomass and waste production To keep the balance one must keep on dosing carbohydrates.
Biopellets!? What happens when the avaiable carbohydrates can not be used due to insufficient Phosphate supply in the reactor? What if the supply of carbon hydrates is interrupted for some reason?
Normally heterothropic assimilation is limited by the amount of available organic carbon = organic matter. Because of this limited availability, the usable organic waste will be used till nothing is left, leaving only a small amount of unusable detritus.
Due to adding of unnatural carbon hydrates it may be that the available organic waste is no longer the limiting factor but the available usable phosphate. Will the easily available carbohydrates be used instead of the organic waste?
The key question is: what to do with the increasing biomass ?
Carbon hydrate dosing is common practice in aqua-culture systems. For a manager of a aquaculture system the question is certainly not a dilemma, it is a goal! After a period of time he will harvest the cultivated biomass and start again.

I prefer a method that removes nitrogen compounds from the system the moment they become available instead of storing them into biomass and have to wait what will happen. Both ways will have there pro's and con's
Carbon dosing can help in keeping the balance if the use is limited, as an aid to balance the food chain.

 

[Randy Holmes-Farley]

NO3 ( + phosphate +?) + carbohydrates = protein Protein + consumption= biomass + ammonia ammonia + seawater = NH4+ NH3 NH4 + nitrification ( alkalinity consumption) = NO3 NO3 + carbohydrates = an ongoing chain of biomass + ammonia production which includes the nitrification process. Biomass grows and stays in the system!
At high C:N ratio the chain will be from NH4 to NH4 without nitrificition because no nitrate will be formed as all ammonia will be assimlated. The assimilation of NH4 consumes alkalinity! The produced biomass stays in the system!
The produced protein must be consumed or removed to have any effect on the nitrogen and phosphate concentration in the water column. The effect is limited to the increasing biomass and what may be removed by the skimmer. All will be recycled when the cultivated biomass dies off. At the end of the food chain this will be the fish which feeds on the organisms fed by the produced protein. To have no effect on alkalinity on must wait till the fish is decomposed and mineralized.!? The protein removed by the skimmer = alkalinity loss.!?

I don't understand exactly what you are claiming, so I may just be re-explaining something different than you are claiming. But I will state once again that the following process has no effect on alkalinity:

fish foods ---> ammonia ---> nitrate ---> organism tissues

That process has zero effect on alkalinity.

 

[Randy Holmes-Farley]

I prefer a method that removes nitrogen compounds from the system the moment they become available instead of storing them into biomass and have to wait what will happen. Both ways will have there pro's and con's
Carbon dosing can help in keeping the balance if the use is limited, as an aid to balance the food chain.

Why do you care if a fish or coral gets bigger? That seems the goal of reefkeeping.

I agree that carbon dosing has benefits, and is why I think it a good idea: reduce nutrients and feed filter feeders. Dosing ethanol or acetic acid will have no lasting effect on alkalinity.

 

[Victoria M]

It's like they're speaking Klingon to me. Whew... Way over my head.

lol, except Klingon, I might have caught a phrase or two.

 

[Belgian Anthias]

It seems that my explanation about the cycles created by adding supplemental carbohydrate was not correct. The cycle from NO3 to NO3 will probably stop at NH4 and become NO3 to NH4 to NH4 as no or little nitrification takes place at a high C:N ratio. When carbon is dosed hetertrophs will fist use the available ammonia by priority before they will be able to use nitrate as there assimaltive Nas system is suppressed by ammonia and because of the high energy consumption needed. As the grow rate of heterotrops is about 40 x the growth of autotroph nitrifiers, nitrifiers will be suppressed in the competition for oxygen and other building materials. As ammonia is used fast by the heterotrops less ammonia is available to be reduced by autotrops. At high C:N ratio this may lead to a very limited nitrification capacity. In most LNS systems a high C:N ratio will be created when carbohydrates are added. Correct dosing based only on the nitrate level seems to me not possible as the hetertophic bacteria are triggered by available ammonia and not by available nitrate. Most published receipts are not based on C:N ratio but on the nitrate level.
As it takes +- 15 days for autotrophs to double there biomass ( 1 day for heterotrops), what will happen when after a period of time maintaining a high C:N ratio for some reason the dosing is interrupted or stopped? At that moment the tank may be in the same situation as a new tank. A full loaded and active tank vulnerable for the new tank syndrome.

The carrying capacity of the system is determined by the capacity of the system to reduce ammonia. (Spotte, S., 1979. Fish and invertebrate culture: water management in closed systems, 2d ed. ed. Wiley, New York.)

Normally ammonia is reduced +-2/3 by autotrops and +-1/3 by heterotrops .
The question is: "What to do with the produced nitrate?"
When nitrate is reduced by denitrification the nitrogen is removed from the system, not recycled within the tank. The carrying capacity of the tank is maintained at all times also when denitrification is interrupted or stopped for some reason.
When nitrate is reduced by organic carbon dosing the ratio between autotroph and heterotrop ammonia reduction will change. When dosing is based on the nitrate level the ratio may become 2/3 to 3/3 heterotrophic. Most of the carrying capacity of the system will depend of the carbon doses. When dosing is interrupted or stopped most of the carrying capacity may be lost. Must we take that risk to "fine tune" something as nitrate?
The question is:"What to do with the biomass produced?" Cultivate scrimp in a refuge and harvest them when they are big enough for consumption!?;Happy

Does heterotroph ammonia reduction consumes alkalinty? In aquaculture systems based on organic carbon supplementation, alkalinty is consumed and must be adjusted. In these systems no nitrification system is installed.
Following Ebling ( Ebeling, J.M., Timmons, M.B., Bisogni, J.J., 2006. Understanding photoautotrophic, autotrophic, and heterotrophic bacterial based systems using basic water quality parameters, in: Proceedings of the 6th International Conference on Recirculation Aquaculture. Roanoke, VA. pp. 270–279.) 3.57 g of alkalinity (0.86 g inorganic carbon) and 15.17 g carbohydrates (6.07 g organic carbon) are consumed for every g of ammonia–nitrogen converted to microbial biomass when carbohydrate is added as supplemental carbon.
Ebling en Co do take in account decay and alkalinty shift.