I was just finishing up my water change for the week and cleaning out the media in my filter (Cascade 700 canister) and the top to screw on for the intake hose snapped. It is a used filter that I got from the owner of a LFS that had taken down his tank. How long will my tank be able to last without the filter?? I don't how long it is going to take??? I'm going to probably just go buy a new filter.