Well, last night I finished plumbing. Here are a few pics. As you can tell by my photos, I am a huge fan of spaflex.
Completed Water change station:
Herbie overflow. The center line is the supply for the closed loop pump.
Closed loop pump (Iwaki 70rlt) running into a 1" SCWD
Closed Loop returns. These elbows are temporary. Still have to plumb the final ones together. Each side will have two eductors. One pointed towards the front center of the tank and the other pointed towards the rear center.
I should be pushing close to 4,000gph out of the Iwaki this way. The current will switch from side to side every 50 seconds. Between the closed loop and the wavy seas, there should be close to 5,000 gph of very random flow in the display. If needed, I will add three mp40s along the bottom of the back wall to keep detritus in suspension.