The water flow in the tank is provided by six Tunze 6100 pumps running on a Tunze 7095 Multicontroller plus a branch adapter. We started with four of the Tunze 6100’s for the first 14 months of the tank’s life and eventually felt the need to add two more as the corals grew out and started to create areas of dead flow in the tank. The return from the sump is provided by an Iwaki 40RLT, which adds roughly 750 more gallons per hour of flow into the system.