best place for powerheads?

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.


FWIW, PH's won't "draw in oxygen"...they pump liquid. What they can do is increase your surface turbulance, which promotes gas exchange (CO2 out, O2 in). Bringing water up from the bottom of the tank helps insure that all of the water in the tank is able to make the gas exchange at the water's surface. Since CO2 is heavier than air, it tends to collect at the water's surface, and the surface turbulance helps to drive it off and allow O2 to enter the water.
If you have lots of detritus collecting, it suggests that you have one or more "dead spots" in your tank. You want to add flow to these areas so the detritus can't settle out, but instead will be skimmed into your overflow (O/F). WHERE to aim them will be a trial and error type of thing. You also want to be sure you're not blowing everything in your tank (fish, coral, CUC, etc) around too much.
If your tank is brand new, try gently wiping the detritus off of the affected areas as it can settle out in places where it normally wouldn't just because of the sheer amount of it sometimes.
I dont have any corals, just fish and live rocks. I tried using an algae scraper but it just swirls around and eventually resettle back. I will siphon them off on my next water change but in the meantime want to reposition the PH for best results. So its ok to move it below and point it up?