Regarding the omniflex tho...in Dez' build they appear to be 45deg fittings. Would that not push flow up and work against the sump returns? 90s would push all the way to the end (all working together) and then hit the pane and go up and then pushed across the top. Maybe the 45s are better what do you think? Better for a sandbed I'm sure.
Two more outlets:
