Nitrate and filtration

[|squee|]

Is it possible that some portion of the nitrate you add through loose ferts (KNO3) gets lost due to BB in the filter converting it to N2 gas?

[vinz]

I don't see why not?

[|squee|]

Ok, if so, here's a wild thought I had: Is it possible that your BB is so damn good that your nitrate gets depleted really fast? Just a wild thought

[KeIgO86]

I remember reading somewhere that BB only feeds on ammonia and nitrite. The bacteria turning nitrate to nitrogen requires an anaerobic environment to survive, meaning its environment has to be deprived from oxygen. In that case, with all that tank water running through your filter media, i doubt they will survive there.

Correct me if I'm wrong though.

[PeterGwee]

Ok, if so, here's a wild thought I had: Is it possible that your BB is so damn good that your nitrate gets depleted really fast? Just a wild thought

Don't think too much... In a highly aerobic environment..very rare except perharps in the substrate floor where O2 isn't getting to.

Regards
Peter Gwee

[Justikanz]

BB = beneficial bacterial? They won't start to feed on nitrates unless it is an anaerobic environment, as pointed out by KeIg086 and Peter... Otherwise, we won't be interested to perform water changes! (Which serves to removed nitrates)...

That said, there is a school of thought that teaches aquarists to use the plenum(sp?), a space under the gravel for anaerobic baterial to grow and draw nitrate converting it back to N2... But that empty space will most likely accumulate (fine) dirt over some time...

[aquarius]

Correct me if i'm wrong but i think marine setup has equipment to get rid of nitrate. If you are able to get rid of nitrate, am i right to say that you won't need to change water cos the ammonia and nitrite is already been taken care of by the aerobic bacterias?

[Justikanz]

If my memory didn't fail me, marine setups use thick gravel or a plenum system to create an anaerobic layer at the bottom for growing anaerobic baterial to consume the oxygen from nitrates and thus converting them to nitrogen.

[Johnc]

That said, there is a school of thought that teaches aquarists to use the plenum(sp?), a space under the gravel for anaerobic baterial to grow and draw nitrate converting it back to N2... But that empty space will most likely accumulate (fine) dirt over some time...

Hmm... that's my school I know it is against most expert opinions, but I use an UGF with low circulation to achieve that (partly to reduce water changes)

Anyway... although BB does convert KNO3 into N2 in an anaerobic process to get O2, other BB produce NO3 from NO2!

Nitrosomonas bacteria converts the highly toxic ammonia (NH3) into less toxic nitrites (NO2) in an aroebic process.

Then nitrobater bacteria found mostly in the filter and substrate converts nitrite (NO2) into nitrate (NO3).

Some NO3 is absorbed by the plants.

What this means is if you are feeding the fish sufficiently, you do not need to add NO3.

Indeed, there is often excess NO3 build-up unless the tank is very heavily planted. These must be removed by water changes or converted to N2 by anaerobic bacteria lower in the gravel (or undergravel!). (In a Marine setup, such bacteria is cultivated in the denitrator)

/John

[|squee|]

Ok, I've learnt something here. Thanks!

[Plantbrain]

Don't think too much... In a highly aerobic environment..very rare except perharps in the substrate floor where O2 isn't getting to.

Regards
Peter Gwee

But.........there is also very very little exchange/flux of that same water, since a high rate of exchange would make it aerobic................thus less impact on NO3 levels.

I have a method to test the rate for Flourite, ADA, etc to show the relative NO3 => N2 exchange rates both with and without plants.

It'll be awhile though.

So that is why batch denitrifyers were popular at one point(and 500$).

Regards,
Tom Barr

[stormhawk]

Correct me if i'm wrong but i think marine setup has equipment to get rid of nitrate. If you are able to get rid of nitrate, am i right to say that you won't need to change water cos the ammonia and nitrite is already been taken care of by the aerobic bacterias?

Irregardless of how good the bacteria culture is in the tank or the filter media, one must never forget to do regular water changes.

[Justikanz]

Oh yes, a water change is the best method to get rid of nitrates... Unless our tap water is LOADED with them in the first place... But please do not change more than 20% at one go... IMO, that is not good for the fish... and the filter bacterial...

[bclee]

Many times in a healthy planted tank, you'd be surprised that the tap might actually contain more NO3 than the tank.

BTW, in the high-tech tank where one dose a lot of fertilisers, water change is not just for removing NO3. It is just to prevent accumulation a depletion of minerals. It is like doing a "soft reset" every week when you partially dump old water and re-dose the minerals. This way you are removing the minerals that are accumulating and replenishing the depleted ones.

In my low-tech tank, I go without water change for about 2-3 months, and yet I still have to add a little KNO3 once in a while.

BC

[Justikanz]

Oh yes, bclee... Always noticed that the plants always do better with a water change, if the tank water had not been changed for some time... Gee... My medication is taking effect, getting drowsy and get ALOT of typos... Haha... Zzz...