[thirschmann]

I just started a small hex tank (only 60 gallons) with a central overflow and two tunze 6201 which move the water in one direction and then reverse it. I started this because I was interested in the flow possibilities for a BB, SPS tank. I am happy with the flow but I have added two more powerheads. One that points straight down to keep more detrius from settling and another that shots horizontal outward to help create some more random flow for the tank. I also should not that the tunzes are not set so that one turns on and the other is off, I have set them so one is at full power and the other is at the lowest setting and then switch, this helps create a more turbulent flow but the one at full power still moves the entire water column in one direction.

In a larger tank conditions would probably significantly different but it gives you an idea for flow options. I must say that a CL with a OM 8-way with 3 nozzles in one direction, 3 in the other, and two point straight out would probably work well also. There are many options and should be a fun project. Good luck!