I got mine from liveaquaria. I have had him for a few weeks and he has never set claw outside of that mushroom. Kinda strange but he seems really happy there.
Well I only feed what my fish can eat so I almost never have any food that settles, but once in a while I suppose some of the stuff could go that way. I have 4 powerheads all set on a random controller so my flow is never the same.