I've had my UGF and power filter running in conjunction for the last 11 days. I plan on removing the UGF next weekend. I'll move the fish and the power filter to a 10 gal tank while I remove the UGF. Once the UGF has been removed, should I clean my gravel? It was real filthy at first but I've been vacuuming it every few days these past two weeks with my water changes to help get my nitrates down (they're down to 10 now, btw). So I figure my gravel <i>should</i> be pretty clean by now and I don't want to remove most of the beneficial bacteria by cleaning it. Any other suggestions on removing UGF's?