65 Gallon plumbing & flow?

[3twenty5]

I am having a custom 65 gallon 36x18x24 built and wanted your comments on my plumbing ideas, 2 Mag 12 pumps running 1 inch piping to 3/4 returns, one pump will flow the sump/refuge..the other through a closed loop system using a SCWD, the overflow will be 4x6x4 with a 1.5 " drain with a durso pipe. What do you guys think?

 

[conundrum]

Looks sound. A change to consider, I like a clean tank. You could run the closed loop up into the drainback box from holes in the bottom, exit thru the sides and intake from in the box. Since you have 2 high exits already, (need to be) for the other pump, these closed loop exits could be lower and hidden by rock. It keeps the pumps in stand and reduces the plumbing clutter on the back of the tank. Just a thought.