[mr_alberta]

I would change the baffles in your skimmer compartment. The water should flow over-under-over the baffles instead of what you have now (under-over). This will help dissipate the bubbles from your return much more.

Also, as Kevin mentioned, I would put another baffle in the fuge area so that the drain enters that compartment first, then overflows over the refugium. Otherwise you're going to have sand everywhere when the water hits it.