Sometimes, the magnetic impeller assembly can become clogged with debris. To clean off fish waste, mineral deposits, etc., you will need to take the magnetic impeller assembly out of the filter. Take the rubber end cap pieces off the top and bottom. Slide the magnetic impeller assembly off the metal shaft and place both the impeller and the metal shaft in white vinegar. The metal shaft and magnetic impeller assembly should be soaked side-by-side. Do this for two hours and then rinse them in warm water. You can now put the magnetic impeller assembly back together. Check to be sure the magnet and the white blades are connected as one piece. If they have become separated, you will need a new impeller. This separation is covered under our two-year warranty. If you need a new impeller or another part, you can buy replacement parts directly from Tetra.