Make ZooMed Mechanical Filter Sponge your first line of defense! Remove dirt and floating debris from your terrarium or aquarium, improving the water clarity. Reusable and easy to clean Wedge shape, course sponge Makes clean up a breeze Instructions: Remove the top of your Turtleclean 511 Canister Filter and simplyreplace your old sponge with this new one. Cleaning: Rinse filter sponge weekly or as needed. If the water flow (on yourouttake spray bar) decreases substantially, then it is time toclean the filter sponge. Replace filter sponge if you notice anywear and tear.