The Fluval FX6 impeller cleaning is sometimes overlooked when we do our scheduled maintenance, but it shouldn't be. The impeller unit is the only moving part in your FX6. I consider that to be pretty important. Keeping your FX6 clean and running smooth is directly proportional to its efficiency. Not periodically cleaning your impeller can cause damage to the entire unit. The Fluval FX6 canister filter is one of the best in the industry but without your effort to keep all of its parts nice and cl