I know that asking for specific advise on how to position pumps is difficult as this is highly dependant on each tank - and what might work in one - may not be good for another tank. In my 120g SPS reef tank I have several powerful pumps and a wavebox. I think I have a good water flow in the tank, but what method can I use to 'test' how effective is my water flow? I always wonder how best to ensure the most efficient tank-sump-tank flow...any advise?