Looking for feedback on return flow

[mark]

It would work but you'll have to balance flow or majority will come from nozzles closest to the pump. Another way to balance is a perimeter loop (was quite a few posts in Calfo section on reefcentral).

Looks like your pretty far into this but have you considered a separate closed loop. You would be able to get a high flow in the tank without needing to run it all through the sump.

Here's a link to a forum with lots of pictures of CL layout (you can setup without OM valves). http://www.oceansmotions.com/forum/viewforum.php?f=10