Zoo Med Turtle Clean 15 - 501 CanisterZoo Meds Mechanical Filter Sponge is the first line of defense in removing dirt and floating debris from your terrarium or aquarium. Although filters are used to keep your water clean and safe, Zoo Med also recommends weekly water changes of at least 20%. When adding tap water (during a water change) make sure you add Zoo Meds ReptiSafe to remove chlorine and chloramines. Removes dirt and floating debris from your terrarium or aquarium. Improves water