I got a 55 gallon aquarium. It has a hole in the center of the back about 4 inches from the top for a 1.5 inch bulkhead. I was thinking about bushing the bulkhead to 3/4 and plumbing a canister filter to it. Should I just put a bulkhead screen on it or get an elbow and some pvc pipe and make an intake tube that connects to the bulkhead and sucks off the bottom? I have a gl*******s overflow box I'm putting on for a sump to filter from the top of the water already. I actually checked and the hole is a little too high to use for the overflow box, so I'm going to have to do something else with it. Thanks.