I think I may have a detritus problem and would like to move the powerheads so it can blow them into the overflow. My tank is 110 gallons (48w x 30h x 18d). The powerheads are currently sitting at the very top about 2 inches below the surface on both sides pointing directly across to the bottom corner of the other side. I placed it there because i was told it needed to be in a position to draw in oxygen. What would be an ideal position to help remove detritus? They are all over the glass walls and overflow box.