I was suffering the same problem. I was getting detritus build up on my sand in the back of the tank. Once a week..I make sure my hands are free of oils detergients lotion.....and I swish my hand around to make sure everything got stirred up a little. Thats what I used to do, aka I didnt have the money to buy new powerheads. NOW, I have a TON of flow, so if you can add some flow, your corals, fish, and detritus will appreciate it. :)How big is your tank and what kind of flow do you have?

what kind of clean up crew do you have? Heres why I ask. I used to think that the bigger the crew the better.....wrong. You need enough to keep algae under control, and thats it. nothing more. Just because you put 100 hermits in your tank.......doesnt make it cleaner. Your adding bioload....in the manner of detritus pooping crabs and snails. 90% of my detritus is from snails and crabs.....fish poo stays in the water column and gets sucked in by the overflow. SOOOO, how big is your crew? Are they doing more bad than good?

In my 200 i've got 20 hermits, 20-30 turbos, 1 sally lightfoot... as the tank has aged i've noticed less with each water change.

I don't know how much margarita snails poo, but they definately eat 20x what a turbo snail does in a day. I have 3 and they keep my entire 58 gallon clean of major green hair algae.