reason for nitrates going down?

[xkon]

Is there a reason why nitrates would go down in a tank without a water change? I am using the api test kit (which might be the reason itself) and my nitrates were about about 15-20 for a few days and then the next few days were at 10. The tank is a fowlr. What would be the cause of this or do you think its just inaccuracy my testing or the test kit itself?

 

[idisc]

Api nitrate is usually higher than it really is. I would assume it could be a mix between the kit n the process.

 

[Crooked Reef]

Do you have a deep sand bed or dose a carbon source? Also if you have a canister filter and just cleaned it out real well maybe.

 

[thegrun]

A deep sand bed, a refugium with macro algae or dosing a carbon source would all remove nitrates. Test kits that are not accurate or testing errors could also explain the drop.

 

[xkon]

So there is no sump/refugium, no carbon dosing, no other filitration other than the live rock and HOB skimmer. I do have sand, 60 gallon tank with 60lbs of sand, so roughly all the sand is under 2" give or take a little in some spots.

So i'm guessing this leads it to being in the api test kit? maybe I should look into another kit?

 

[thegrun]

The API test kits are not the most accurate, but for a fish only tank does it really matter if your nitrates are at 10ppm or 15ppm? You may want a more accurate test kit if you are keeping corals, but even then API will let you know the general level of your nitrates. I use more accurate test kits myself, but for many of use a higher resolution isn't necessary. If you plan on keeping stony corals I would recommend better test kits at least for calcium, magnesium and alkalinity.

 

[xkon]

I dont plan on any corals for the tank, so I guess the exact level of nitrates isn't a huge concern. around what level of nitrates should facilitate a water change?

 

[wooden_reefer]

So there is no sump/refugium, no carbon dosing, no other filitration other than the live rock and HOB skimmer. I do have sand, 60 gallon tank with 60lbs of sand, so roughly all the sand is under 2" give or take a little in some spots.

So i'm guessing this leads it to being in the api test kit? maybe I should look into another kit?

Denitrification can be happening esp in the deeper part of the LR.

Denitrification happens when there is less O2 and esp when there is the right organic matters as food.

In denitrification, nitrate's role in oxidation-reduction is similar to that of O2 in nitrification.