Hey all, I replaced my UGF with a new Emperor 280 penguin Bio Wheel and so far, im really happy with it except one problem. The impellor makes alot of noise at any speed. It makes this terrible grinding/gurgling noise and it hasn't gotten any better over the last 3 days. Have a got a fautly unit or they supposed to be this noisey? My Top Fin External Filter was alot quieter then this thing.