FEATURES Removes dirt and debris from your aquarium. Improves water clarity. Easy to clean/reusable. Activated carbon included. INSTRUCTIONS Unplug your filter and open the door to access the cartridge. Remove the fouled cartridge and replace with this new one. CLEANING: Rinse sponge material as needed, or at least every 3 weeks. If the water flow decreases substantially, then it is time to clean the filter sponge.