He covered a lot about sump design that he has learned over the years of building and planning out different sumps. Also the mention I made about my flow that is running through my sump which is probably around 600 - 700gph after SQWD etc. on my 58 gallon tank is probably just fine. He mentioned a 10 to 15 time turnover volume through your sump and any more flow you want in your tank come from powerheads, closed loop, etc.
Of course mine looks very calm in my sump as it's almost the same size as my tank. Very good information and you can find all kinds on his website at www.melevsreef.com if you've never been there.