Hi. I currently have a 4'x1.5'x15' (65gal) tank which is filtered exclusively by a 20gal sump. The sump was setup above the tank for the time being with a powerhead until I could get a real pump and place it below the main tank. I have purchased a 420gph pump and want to know if this is enough? Also I had originally made the baffles 11.8" high and the sump is 13.7" high. Is this to high and will the sump overflow during a power outage or is this the correct height. If not what should the height be. Also what diametre pipe should the overflow be 2"? I have a 1" return is this correct? Thanx for your help.