I usually have mine submersed a little going into a micron dock. Keeps it a little quiter so u don't here a splashing sounds. Bit if ur running glass tops, I would cut it higher and let it splash to help with oxygen exchange.
You don't have the fuge and skimmer on opposite ends and the return in the middle? Makes for much more efficient skimming/natural filtration by allowing slower flow through the fuge.