water flow?

[TheReefGeek]

I would match the draining gph to what your skimmer needs, then feed the overflow water right into the skimmer, this way the skimmer is dealing with all the crud from the surface of your water and it is the most efficient.

Also with too much sump turnover, you could have a microbubble problem.

As suggestions, get the tank drilled for a closed loop, or go with "nicer" powerheads like Seio's or tunze streams.