My friend has a tank that is roughly 30 gallons. He said the water is cloudy. He has been doing regular water changes. He bought something (not sure what) that is supposed to clear up the water. He said it will make the water clear for about a day and then it gets cloudy again. The tank has been up and running for close to a year now so it should be fully cycled. I don't think he's done anything to kill the bacteria, but I'm not sure. He has tested the water and said the levels were fine. He is using the strip tests which aren't very accurate, but I am going to bring my
test kit to him today to get a better reading. Since I have never had this problem, I don't know what to tell him. Any thoughts on what the problem might be?