I have a built in overflow that empties into a 30 gallon long sump with a LFS made ETSS type protien skimmer driven by a mag 12 and then then the water flows into a MAG 24 with returns the water to the tank via 2 jets which I have positioned to "splatter" the water in every direction. I also have 1 Maxijet 1200 powerhead to move water along the uper back wall. For lighting I have 2 400 watt MH with 6500K Iwasaki bulbs and Blueline E-ballasts. The 6500k lights are a little yellow but to me it looks like the color of water when you dive in shallow areas less than 15ft which is where a most sps and clams grow. Plus you get fast growth. Actinic suplementation is 2 VHO 110watt URI superactinics run by a hellolights VHO electronic ballast.