Nitrate Poll

[Wazza]

As a matter of curiosity just wondering what the average nitrate level other tanks have.

[Ira]

Most of my tanks seem to stay around the low end, 10 or less. But my big tank seems to be either 0 or 70ish when it comes to water change time.

[Warren]

Ranges from approx 5-10ppm.

[Wazza]

Here is a working theory, but it is full of holes.

Wed 12 I harderned the water by adding a white powder that lfs gave me forgot to ask what it was made up of, but will ask tomorrow, old reading was 1dh (18 mg/l caco3) and added active carbon to my main filter (to remove yellow tint), nitrate was 20ppm. new hardness 15 dh (300mg/l caco3), did this to make the ph stable (it kept moving from 6.8 to 7.4), this advise came from lfs, and its working so far.

Thur 13 pm 30% water change nitrate dropped to 10ppm

Fri 14 am nitrate jumped to 80ppm

Fri 14 pm 30% water change tested again, nitrate still 80ppm

Sat 15 am nitrate still 80ppm, removed carbon, did 50% water change

Sat 15 pm nitrate 40ppm

Sun 16 am nitrate 40ppm, another 30% change later today.

Ph is stable at 7.0 does not change, ammonia and nitrites are zero again does not change.

I know carbon does not or meant not to effect nitogen levels, but in all other tests before adding the carbon nitrate never when over 20ppm but as soon as carbon was entered nitrate jumped. I will keep monitoring of course but see no other cause.

As I said a theory. Yellow tint gone anyway.

[Warren]

Some inferior activated carbons release nitrate when added to the tank...