I just installed my aeration yesterday. Max depth of 10.5 feet. Diffuser is set on to of a platform of milk crates (4 on the bottom, 1 centered on top) that puts the diffuser 22 inches off the bottom.

I'm in the break in stages right now, but at that depth, other than at initial startup, I don't see any distribution of bottom particles in the surface water.

Don't know if this helps, but it seems that elevation from the bottom isn't disturbing the bottom very much.

.10 surface acre pond, 10.5 foot deep. SW LA. The epitome of a mutt pond. BG, LMB, GSF, RES, BH, Warmouth, Longear Sunfish, Gambusia,Mud Minnows, Crappie, and now shiners!!...I subscribe!!