Help Nitrate At 80Ppm

[eaglesaquarium]

API Nitrate test kits are rubbish, so inaccurate that they're not worth bothering with, if you want a decent one buy a Salifert one, the reagents are kept separate so they last longer and give more consistent results.

API uses two different reagent bottles for the nitrate test, but I agree that the test is not very consistent! I am having trouble with it myself.

 

[fluttermoth]

Um, the API nitrate test has separate reagents too...

I have to say, I've never had a problem with the API one, as long as the instructions are followed properly. Obviously I've never had the results cross checked by a lab, but they've always been where I would expect them to be, either low or high (so rainwater tests at between 0 and 5ppm, LFS water over 80ppm).

 

[StandbySetting]

There are 3 reagents required for the nitrate test kit, in the API kit 2 of them are pre-mixed together and the solution will slowly degenerate over time.

 

[ian]

and just to add that most off the shelf test kits transform nitrates back into nitrites before measuring the combined values. This is only of importance if nitrites are present. Since nitrites are at 0 in established tanks, this “combined reading” is accurate regarding nitrates. If nitrites are present, the nitrate value is the combined measurement, resulting in an actually lower nitrate concentration as indicated.

 

[fluttermoth]

There are 3 reagents required for the nitrate test kit, in the API kit 2 of them are pre-mixed together and the solution will slowly degenerate over time.

Oh, ok; I had no idea there were three! Thanks

 

[eaglesaquarium]

and just to add that most off the shelf test kits transform nitrates back into nitrites before measuring the combined values. This is only of importance if nitrites are present. Since nitrites are at 0 in established tanks, this “combined reading” is accurate regarding nitrates. If nitrites are present, the nitrate value is the combined measurement, resulting in an actually lower nitrate concentration as indicated.

That might explain my nitrate readings!!!


So, if nitrites are high, nitrates will be read as lower than they should or they will appear to be higher than they should be?


For example, in my cycle my nitrite readings were zero, but the nitrates read 40ppm. Now my nitrite is off the scale and my nitrates are reading 5-10 ppm. Is that normal or am I still conducting the nitrate test incorrectly?

 

[ian]

when i say 'most' test kits, i couldn't tell you which ones. It could be worth dropping API a email to ask.