I was wondering about this on my 125 as well...
I've got 3, XP3's filtering it. I've got a spray bar on the right side-top of the tank and a "jet" on the left side-top of the tank to break up the surface tension. I've also got a spray bar on the left side about 1/2 down the tank pointed toward the substrate.
Most of the detrius settles on the right side of the tank.