I use an old 801 every now and again. Move it from tank to tank. I 'll let it hang in one side for an hour or so, then move it to the other side just to stir things up from time time.
Quickest way to clear the bottom of my fry and grow out tanks too. Blows every thing up in the water column for the overflows to grab.
I don't use them full time only because I fight to keep my temps down here in florida and any watts in the water add up.