Actually, there is only 3460gph with the two 1500's and the two MJ 900's (230gph x 2) in the tank, then add on probably around 900 or so gph with the return. When you look at the tank, you can see there is flow from the motion of the LPS, GSP, anemones, etc, but there is still some stuff that makes it down to the sand and kind of hangs out there. I'd like to keep it moving a bit better than that. It's really not that much when you see it.