The impeller for your aquarium filter is crucial to having it run efficiently. You should be removing and cleaning your impeller each time you clean your aquarium. Having it clean will make sure your fish tank filter will last a long time. Eventually, the impeller in your filter will wear down. You will often hear a crunching noise or your filter will stop running. At this time, you should replace the impeller in your filter. Our Aqua One impeller sets are ideal for keeping your filter running smoothly for years.