Sorry to dig up an old thread but this is exactly where I have been stuck for the past few weeks. I have a 7' long 420 gal tank with two of the 20" Shadow overflows setup in a beananimal configuration. The return pump is a Reeflo Super Dart / Snapper Gold Hybrid (4300⁄2400 GPH) that has a 2" FPT inlet and a 1.5" FPT outlet. I already have three return points -- one on each end and one in the center. I ran 1.5" pipe from the return pump up to the tank and then reduced that to 3/4" bulk heads with 3/4" Loc-lines. Since there are three returns, do you think this will work? If so, maybe I can fill it up and get it underway. I have waited to add water because of my uncertainty in this set up. Any advice is greatly appreciated. Thanks in advance!