Impeding Denitrification?

[VR28man]

In this thread:

Does high nitrate cause browning of SPS?

Elevated nitrate = coral dying High nitrate = algae/coral browning Zero nitrate = coral dying High phosphate = algae/stunted coral growth/coral skeleton brittleness Zero phosphate = coral dying All the above make me dizzy and it only cover a fraction of nutrient levels effects on corals/reef...

www.reef2reef.com

@jda posted:

Why do you have nitrates? Most tanks with some sand and a good portion of real live rock have no problems keeping nitrate at zero, but it can take up to a year if you left everything alone for nature to do it's thing.

Are you bare bottom? Keep minimalistic rock scape? Is your rock man made or previous dry/dead? Have you impeded he last part of the N cycle (nitrate to N gas) with organic carbon, GFO, euro dosing regime or anything? Is your tank still pretty new?

Figuring out why you have nitrates could change your approach.

I have 2-3" of sand and a bunch of real pacific live rock. No matter how much I feed, the anoxic bacteria will keep the N about .1 or lower and there is nearly nothing that I can do to raise it including adding KNO3.

Rather than reopening that two year old thread, I decided to start a new one.

So, does this imply, if you use GFO or carbon dose, you can impede an aquarium's natural denitrification?

 

[Randy Holmes-Farley Verified Community Expert]

In this thread:

Does high nitrate cause browning of SPS?

Elevated nitrate = coral dying High nitrate = algae/coral browning Zero nitrate = coral dying High phosphate = algae/stunted coral growth/coral skeleton brittleness Zero phosphate = coral dying All the above make me dizzy and it only cover a fraction of nutrient levels effects on corals/reef...

www.reef2reef.com

@jda posted:



Rather than reopening that two year old thread, I decided to start a new one.

So, does this imply, if you use GFO or carbon dose, you can impede an aquarium's natural denitrification?

Im not sure exactly what you are asking or why. A more specific question might be easier to answer than the vague general statement based in that thread.
For example, organic carbon dosing will not ever cause nitrate to rise even if it does theoretically impede nitrate consumption rate simply because it causes some bacteria to take up ammonia directly.

if phosphate is excessively low it can impede growth of many organisms which might result in reduced consumption of nitrate.

 

[taricha]

In a practical (though anecdotal) approach to the question... Sometimes hobbyists find that carbon dosing to reduce nitrates is ineffective if PO4 is zero. And adding PO4 allows carbon dosing to reduce nitrates significantly.

 

[VR28man]

Thanks, Randy, and my apologies if this seems cryptic.

The last stage of the nitrogen cycle is for the nitrate to turn into nitrogen gas and leave the aquarium.

It is asserted that this final stage of the nitrogen cycle can be impeded, at least in some case, if you dose if organic carbon, use GFO, euro dosing, etc.

If this is true, I curious as to why, and some more explanation. (hopefully this is a bit clearer. )

 

[Dan_P]

It is asserted that this final stage of the nitrogen cycle can be impeded, at least in some case, if you dose if organic carbon, use GFO, euro dosing, etc.

If this is true, I curious as to why, and some more explanation. (hopefully this is a bit clearer. )

Here is my take on the answers posted already.

Dosing organic carbon causes heterotrophic (presumably) bacteria to consume nitrate and other nitrogen containing compounds. This means less nitrate is available for conversion to nitrogen gas, but no nitrate accumulation.

GFO can starve a system of phosphate, resulting in slower growth and possibly, lower nitrate consumption. Some organisms will suffer more than others under these conditions though I can’t say whether the bacteria involved in nitrate reduction are particularly sensitive to very low phosphate concentrations. I have observed during carbon dosing experiments that when phosphate becomes undetectable, nitrate consumption stops, but restarts upon the addition of phosphate.