Ummm, long time no see, huh, good question 4 me to, I'm going to be putting 2 powerheads in my 60 gallon hex, K. now because it's a hex(I wish I had a normal tank)lol, there is no cuculation on the bottum because my flval output is way up top, so I'm going to place the power heads about 5 inch down and point at bottom. Does this sound good??? and I'm going to go with good(powerfull powerheads so they can reach the bottom, or enough to kick it up a lil) thnx see ya around *PEACE!* *PEACE!*