Nitrates Not Increasing

[Ollie05H]

I have 2 reef tanks: one 35L all in one and a 90L both between 1-1.5 years old. For the past year or so my nitrates have been at 0ppm. Recently, my corals have been seeming a little less happy as normal and slower growth. For this reason, I bought reef zlements nitro plus to supplement my aquariums with some nitrates.

I have done around 4 doses (which is meant to raise it by 1-2ppm each time). Every time I dose, I retest after 24 hours, and it is always still 0ppm (even after dosing a little over the max recommended dose).

The 90L has a refugium which may contribute to this, however I have no idea why the 35L never raises. A short while ago, I switched to fortnightly water changes (from weekly) which I was hoping would help but had no effect.

Does anyone have any suggestions or any possible reasons why this might be?

 

[Randy Holmes-Farley Verified Community Expert]

Dose more each time.

Assuming your kit works, it is just being consumed.

 

[Ollie05H]

Dose more each time.

Assuming your kit works, it is just being consumed.

We have tried using salifert nitrate test kits and Hanna nitrate pocket checker. The bottle says to only dose 1-2ppm per 24 hours.

What could be consuming the nitrates?

 

[Jedi Knghit]

Corals and algae both consume nitrates.

I am not the most experienced reefer around, but you have a few options.

1. Increase the dosage of nitrates until you get a detectable level then figure out what dosage you need to maintain it.
2. Feed more
3. If you have a skimmer, you could skim less (tune the skimmer to skim less or turn if off for part of the day)
4. If you have a refugium, you could cut back on the lighting hours to slow the growth and uptake of nitrates

Just pick one and stick with it.

 

[Ollie05H]

Corals and algae both consume nitrates.

I am not the most experienced reefer around, but you have a few options.

1. Increase the dosage of nitrates until you get a detectable level then figure out what dosage you need to maintain it.
2. Feed more
3. If you have a skimmer, you could skim less (tune the skimmer to skim less or turn if off for part of the day)
4. If you have a refugium, you could cut back on the lighting hours to slow the growth and uptake of nitrates

Just pick one and stick with it.

The 35L has a small skimmer which I don’t think is very effective with not a lot of algae around to consume it.
I have tried reducing the lights in the refugium (in the 90L) and that’s not made a difference so far.

I don’t like raising it too much as the bottle says to raise it by 1-2 ppm. Will it affect my corals/fish if I raise it by any more?

 

[Randy Holmes-Farley Verified Community Expert]

We have tried using salifert nitrate test kits and Hanna nitrate pocket checker. The bottle says to only dose 1-2ppm per 24 hours.

What could be consuming the nitrates?

Anything that photosynthesizes. Algae, corals, anemones,etc.

 

[Ollie05H]

I can confirm it is likely being consumed by my corals, I just dosed 2ppm and tested 15 mins afterwards. The level is now at 2.5ppm. I’m not experiencing very good growth atm and in terms of livestock I would say they are both relatively overstocked so I am a little confused where so much is going.
Is this normal? And will my corals (especially sps like acros) be annoyed if I’m jumping the nitrates from 0-2.5 every day?

 

[Randy Holmes-Farley Verified Community Expert]

I can confirm it is likely being consumed by my corals, I just dosed 2ppm and tested 15 mins afterwards. The level is now at 2.5ppm. I’m not experiencing very good growth atm and in terms of livestock I would say they are both relatively overstocked so I am a little confused where so much is going.
Is this normal? And will my corals (especially sps like acros) be annoyed if I’m jumping the nitrates from 0-2.5 every day?

No, they will not be annoyed, except by low levels.

 

[Ollie05H]

No, they will not be annoyed, except by low levels.

Ok, thanks a lot for the help, I’ll keep dosing more and more till I get a steady level of around 2.5. I might spread this dose over a few times a day though to make it a little more gradual.