I have a Marineland Penguin Bio Wheel 150 on my daughter's 10 gallon tank. I've never touched the bio-wheel, other than to clean the "bearings". I usually rinse the filter in tap water once a week, and totally replace it at 2-3 weeks. If I don't rinse it after a week, then the bio-wheel slows and eventually stops. Am I doing the filter cleaning/replacing correctly? I was told that the bio-wheel would hold the bacteria, so I wasn't worried about the filter. Should I be using the filter longer? Her tank is stocked with: 2-platys 2-dalmation mollys (turned all black now) 2-Rainbow fish 1-chinese gold algae eater 1-angel fish I ditched the filter that came with the tank shortly after I set it up, and replaced it with the Marineland Penguin. The tank is fully cycled, and has been running for over a year w/o any problems. I was just browsing the forums and I saw where people are saying NOT to change your filters, so I'm now confused on how I should be treating the filter.