question about nitrite

[kmlong]

I'm only into this hobby 4 months now and not a day goes by that i can't stop and look at that aquarium!!!! How I wish i could just jump in there and join them. Anyways, I have learned alot from you great people, how to cycle, etc. But i was thinking last night and could not answer myself. How comes if bacteria is always present (after cycling of course) there aren't constant nitrite readings? Would this be where the nitrate comes in? The nitrate eats the waste from nitrites correct? So you've got 3 things going at once: ammonia, nitrite, nitrate. Nature is amazing!! Ok, guess i answered myself by writing out the question. I do that a lot when i post. well feel free to comment anyways!

 

[TankGirl]

Fish produce ammonia - nitrifying bacteria (present everywhere) grow and consume ammonia and produce nitrIte, denitrifying bacteria grow and consume nitrIte and produce nitrAte, so all you will ever see in a cycled tank is the nitrAte, since (in the absence of plants, which use the nitrate as fertilizer) bacteria don't consume it.

I think you got it, kmlong Based on your posts I would not have guessed you were in the hobby only 4 months - kudos to you!

 

[kmlong]

I've done lots of reading and lots of experiments and learned from my mistakes

 

[shadofax69]

actually the denitrifying bacteria do not turn nitrite to nitrate that is still nitrifying bacteria. denitrifying bacteria actually live in anerobic areas where there is little oxygen. The bacteria uses the oxygen attached to the nitrate to live and gives off nitrogen gas. These types of regions can be created using a fine sand or other substrates with fine grain size.

 

[TankGirl]

Thanks for providing some science to this discussion, LOL! I need to choose my words more carefully -

 

[deeni0z]

anaerobic bact.

DeNitrate claims to support anaerobic bacteria, as well as DeNitrate. Anyone have a product review of this?

 

[TankGirl]

This product supports bacterial growth. So does gravel and filter media. What's the difference?

I have not used it, so I should keep my mouth shut, but I'm eager to hear about it as well.

 

[deeni0z]

I'm just concerned about anaerobic bacteria. I read somewhere that anaerobic converts nitrates back into nitrogen... but isn't nitrogen still bad?

 

[Voodoo Chilli]

I'm not familiar with this "Denitrate" product: I still endorse the free method of removing nitrates: regular water changes.

 

[Medusa Head]

The reason that there aren't constant readings is that the bacteria is very active. The ammonia-eating bacteria are more active however that the nitrite-eating bacteria. The nitrite-eating bacteria needs a lot of oxygen. So, if you have low dissolved oxygen levels and a well stocked tank, you will have constant nitrite readings.

Quoting myself from another thread,

Anaerobic bacteria really doesn't prefer nitrAte. It prefers oxygen. In most tanks, since low oxygen levels will kill fish, anaerobic bacteria doesn't do much to nitrAtes. What happens is when dissolved oxygen is low, the anaerobic bacteria can get oxygen ions from the nitrAte molecule, so it breaks the nitrAte down to nitrogen gas and oxygen.

In order to use it in an aquarium, you have to set up some means of creating a spot where aquarium water can go and lose oxygen. In order to do this, a "sump" has to operate at an extremely low flow, at about 1 drop per second. It also can't have any dead spots, or the bacteria will turn septic and give off dangerous gases like hydrogen sulfide.

There are companies who makes "nitrAte filters" that work within the above parameters. The most widely sold ones are by Aqua Medic.

I have yet to try one. I understand these units need to "cycle" seperately from the rest of the tank, and just like the main tank it takes 4-6 weeks.

As for "nitrAte absorbers," again they really don't absorb nitrAte directly. Rather, they absorb dissolved organics that would otherwise end up breaking down to nitrAte. The bacteria in the tank that is processing nitrIte will still produce nitrAte.