hey shivvy, I here what your saying about the return pump being weakened...based on the fact that my return is only a qo4000 I dont really have the gph to spare, I thought about really doing what was suggested but decided to avoid any loss in gph! I want all I can get.
As far as the om 4 way goes I went to the om froums and asked apul directly, he told me that the sequence really didnt matter. If I go with 1 and 3 as the two top returns my flow would be more parallel and that a top and bottom 1 and 3 would create more of a swirl affect. He is very much an advocate of the rolloing affect flow pattern when you are running a horizontal overlfow. meaning push the top water down the back wall (including return) and the lower retruns push forward and upward.