Powerhead Placement

[joemc]

Where is the best place to put powerheads in the tank. I have a 29 gal cube. Are they better towards the top or bottom?

 

[snipe]

Some have them at top and mid level dont want them at the bottom they will suck up the sand and such or small inverts. I have all of mine at the top 2 bigger ones blowing up and to smaller ones blowing down. I think I might try and take off the big ones tubes so it blows strait and blow the small ones up.