Nitrate Levels

[Beverly]

Originally Posted by danny zubot

I don't think you will need to do a couple of 50% water changes, it seems like a bit much for that level. Try just doubling what you normally do and that should bring them down a bit more.

A 10% water change will reduce the nitrate by 10%, in this case, 2 ppm. If doing a 20% water change, nitrate reduction will be 4 ppm. A 50% water change should reduce nitrate to 10 ppm. A second 50% water change will then reduce nitrate to 5 ppm.

As well, you will also be dramatically reducing phosphate by doing large water changes, which may save you a cyanobacteria outbreak somewhere further down the line.

To test your test kit, take a sample of tankwater and dilute by 50% with RO, then test the diluted sample. You may also test your RO water for nitrate to see if nitrate is entering your system during water changes.