I have a 300 gallon tank with many fish in it. I keep testing my water alot. My ammonia (NH3/NH4) and NO3 seem a little off. My NO3 is right at 40ppm. i Know that fine but my NH3/NH4 is at .50ppm and has been that way for weeks. I only feed 3 times a week as well and just enough. I did get ick about 3 weeks ago and treated. Im just worried because i have some fish that are worth alot of money. They seem to be doing good and there all eating. I have like 3 fish that have one eye thats a little cloudy but not to bad. I did do some water changes like normal and i use aquarium salt. I have a fluval fx5 and wet dry setup. Anyones help will be good. Thanks