Bthatcher

parameters have been double checked, they are all good. there is a small film on the top, what does this mean? I'll look into getting another air pump for this tank 24/7

its 50 gallons with 13 fish, with an aquaclear 110. I find myself constantly putting an airstone in the aquarium because I can tell the fish are suffocating. I usually leave the airstone in there overnight and by morning they are fine. 2 days later they are stressed as heck, won't eat and gasping and yawning like they have no air. anyone know what up? thanks. ammonia nitrite:0 Nitrate 20 temp: 80 PH: 7.6