Why? The tank is a 180. I am using a 75 diy wet/dry. I did tear out the overflows clean them with water and resealed them in and the whole tank with the aga silicone. It was previously used a couple of years for saltwater. It has been set up for 3 months now. After I resealed it I did a water test and filled 6 inches of water in it and after a couple of days the water turned completely white and stunk like chlorine or something. Why is this still doing this? It doesn't affect the fish or anything but it is not nice to look at.