well as AW stated it is drilled with dual returns on each side ,however we have had to do some modifications to the returns due to lack of waterflow. we now have it set up for just dual returns and then the center returns are now closed loop we have a proclear 300 wet/d dry for filteration dophin ampmaster 2700 extrenal return pump .the closed loop has a quiet one external pump.venturi protien skimmer and a mag 7 pump for that.but will be revamping everything soon as for photos of the filteration i dont have any as of yet and as always my kids keep steeling my camera batteries grrrr.. having a tank at this depth as a reef is very difficult to get a good water flow the way this one was designed just wasnt enough to get full tank movement se we are still working on perfecting this.ps no sump yet i still have to have one ordered