I have a mag 12 at about 4-5 feet. I have no 90 bends. They were all replaced with 2 45s. Im thinking im getting around 600-800gph not quite sure but somewhere in between. Most of bubbles are coming from the water fall effect from high flow of water. Ive been trying to fix this for a few days and its starting to make me frustrated. Ive sealed all the piping so theres no more leaks. Overflow and waterfall is what causes all my bubbles. If you can please help me find a way to stop them from entering my tank.