Bacteria: eliminating ammonia force bacteria to eat nitrate?

[T206]

Title says it all. I have another nitrate related question. If I can strip all the ammonia out of the tank before it is converted to something else can I force the bacteria in my system to be more aggressive towards consuming nitrate. One forum member mentioned my bacteria isn't processing nitrate because it is consuming ammonia directly.

[bertoni]

I doubt that's true. I am assuming that the tank has zero measurable ammonia on a hobbyist kit. Does the tank have live rock?

[tmz]

Stepping back a bit.

Ammonia is produced via purification /decay of organic matter , primarily foods and waste products in aquariums on an on going basis. So. while it should be undetectable for a healthy tank it is continuously being produced in a fed living aquarium. The more you feed the more you'll get.

Fortunately, ubiquitous chemolitotrophic ammonia oxidizing bacteria nitrify the toxic ammonia and together with nitrite oxidizing bacteria they ultimately produce nitrate in a tank that has completed the nitrification cycle.

When organic carbon levels are increased via organic carbon dosing or otherwise . heterotrophic bacteria flourish and take ammonia preferentially for the nitrogen in a one step process without producing nitrate; they compete with the ammonia oxidizers and are likely to limit them to some degree. These heterotrophic bacteria also assimilate some nitrogen and also engage in anaerobic activity when free oxygen is unavailable reducing any available nitrate along with other denitrifiers via a conversion of nitrate to nitrogen gas which bubbles out of the water.

So; if you are dosing organic carbon, less ammonia will be converted to nitrate and organisms preferring ammonia may take some nitrogen from nitrate instead and some nitrate(NO3) will be reduced to N via anaerobic activity with some of that N forming N2 ( nitrogen gas) which bubbles out of the tank .However it's generally takes a while to establish that balance in an aquarium . Sometimes it takes months to reduce high nitrate present in the tank before carbon dosing starts.

If organic carbon levels are relatively low ; more of the ammonia in the tank will be oxidized and more nitrate production as a consequence. Extra surfaces in hypoxic areas such as live rock and/or substrate can provide for increased anaerobic nitrate reduction.

[A1t2o]

There are different forms of bacteria in your tank. During your cycling process you will add ammonia through one form or another, then bacteria that eat ammonia will multiply in your tank and they produce nitrite. Then bacteria that eats nitrite multiply and produces nitrate which is toxic in higher doses, not low does like ammonia and nitrite. Algae absorbs the nitrate and phosphate.

So by eliminating the ammonia you will be taking out the driving force of the entire bacteria cycle. If you are talking about doing this while you are cycling your tank, then I would say NO, that is a bad idea that will make your tank seem cycled when it is not. On the other hand, if you are eliminating ammonia temporarily to deal with an algae bloom or a nutrient spike on an established tank, while taking care of the source of the problem, then I do not see a problem with that.

[bertoni]

I agree that there will be competition for resources, but unless the tank is surface-area-limited, it should be able to develop denitrification bacteria to consume the nitrate. I don't understand what "stripping" the ammonia would mean or accomplish.

[tmz]

I don't think you can strip the ammonia in a tank with life in it.
Adding the organic carbon and the heterotrophs it encourages helps keep nitrogen( including ammonia, nitrite and nitrate ) and phosphate levels low but they as well as the autotrophic bacteria in the nitrification cycle are benthic and need surfaces to colonize . Additional surface area is a big plus for all of them ,imo; I agree a tank can be surface area limited and adding more of it particularly when it has hypoxic areas can reduce nitrate in many cases.

[bertoni]

Okay, that all makes sense.

[Dan_P]

Originally Posted by T206

Title says it all. I have another nitrate related question. If I can strip all the ammonia out of the tank before it is converted to something else can I force the bacteria in my system to be more aggressive towards consuming nitrate. One forum member mentioned my bacteria isn't processing nitrate because it is consuming ammonia directly.

In principle, yes. The difficulty is that the aquarium is generating ammonia all over and the ammonia is either quickly dispersed throughout the aquarium or consumed by nearby bacteria. In this scenario, ammonia is likely to encounter ammonia oxidizing bacteria before your ammonia stripper "sees" the ammonia. The half life of ammonia must be very small in an established aquarium.

If you have a method to strip ammonia, you would be a very, very popular person in the aquaculture industry. What did you have in mind? Is it patented?