Hi everyone. I have a Red Tail Catfish that is getting to big for his current tank so I am setting up a new tank that I decided to put sand in since I don't want him to him to swallow the rocks anymore. But, the tank has been filtering for 3 days now and I keep doing water changes every hour or 2. But, every time the water comes our this solid white color almost looks like its milk. I had the tank almost cleared at one point. But I moved the sand around to get the trapped air out and the water turned milky again. I've been fighting this battle with this tank and losing. Is there anything I can do to fix this? I need to get this tank setup within the next couple of days because the RTC is inside of a 46 gallon tank right now and he's about 10inches right now. Thanks