Question 2, water flow and designs for reef tanks

[reeferaddict]

I have 2 Tunze 6100'sfor main tank flow, 2 separate closed loops on SQWD's for surface agitation, and between 5 and 600 gph on my return on a Sea Swirl, and 2 Seio 1100's blowing the back side of the reef... Somehow the sand doesn't blow all over the water column, but the flow patterns and the Engineer Goby make for some interesting shifts in the "dunes" at times... As things are beginning to grow in and take hold I know I will be adding more though. I'm looking at those 6055 Nanostreams to put on my 7095 controller with the 6100's.