I have a 6 week...65 gallon aqueon tank and have fish in it. Danios, corrys, plecos, tetras, ram chiclids.....all are doing fantastic. However, usign API test drops, I keep reading an ammonia .25 to .50 readings. I have done frequent water changes but to no avail on the Ammonia changing. I have added freshwater plants as well as bags of bio balls to the Aqueon Quiet Flow 75 filter. I have also used the Prime instead of "Water Conditioner" and have used the AmoGuard. My Ammonia levels never change. My fish show NO signs of stress, spots or redness. Petland has the same readings on my sample....Nitrite is 0...Nitrate is 5...my water is clear and i feed the 28 fish once a day..can anyone grace me with their wisdom?