Nitrate and nitrite spike! HELP!

[aibo210]

Hi

my NO3 is at 25mg/l and my NO2 is at 5mg/l is this bad ? and how do i stop this? I have 4 angel fish and 2 clown they seem ok but surely this will afect them !


Carl

 

[tstenback]

Yes this level of NO2 is very bad for the fish. Do a 50% water change right away and do another tomorrow. The nitrate reading is OK nothing to worry about but that nitrite reading is a killer. specially for the angels. The water changes will help with this. After the 2 big changes do 15% daily until the nitrite reading goes to Zero. It appears that your tank is in a cycle for some reason. medication or gravel cleaning and filter media change at the same time? HTH