Hello, I have a DIY UAS on my 75 gal freshwater aquarium. I seem to have established the grow screen based on the instructions here, but haven't yet gotten much in terms of output yet.... I have 2 goldfish and a Pleco in the tank and chemicals I have been testing for are ammonia, nitrite and nitrate. I've heard much about phosphate tests, but I'm not sure if that is applicable to a freshwater setup or not. Should I be testing the levels of other things in the tank?