I test my fish tank in the morning and before bed, I have 0 ammonia Nitrite is .25 ppm yesterday it was 0... Nitrate is always about 5.0. I do 10-15% water change every week and when Ammonia gos anywhere above .25 I was just wondering if I am doing the right thing ? I am still trying to understanding the chemicals and what to watch out for in the tank.. and sorta off topic about the chemicals but. one of my Java fern is growing white stuff on the roots, so I am not sure if that plant might be causing some of these levels?? I have a molly in my 20 gallon right now too.