lol awesome...

well, for my closed loop I decided to go with 2x 1.5 inch bulkheads to drain, at some point they will need to pair down to the size of the pumps plumbing, which is i believe 1", going to the oceans motions were back up to 2 inch (that is the size offered) and each pipe coming off the oceans motions will be a 1.5.

I could be wrong on this, but I think the diameter of the pipe does not so much effect the amount of water going through it, but the velocity of that water... does that make sense? water coming out of a 1.5 inch pipe is going to have a more turbulent and deeper penetrating effect than that coming out of a 2 inch pipe, over all, I think the flows will be relatively close in volume, but I could be wrong in that... someone like Gary, Richard or Tim could easily correct that... I am still very much learning this stuff myself.