Zoo Med 3 Pack of Replacement Fine Mechanical Filter Sponges for Turtle Clean 30 3 pack of replacement Fine Mechanical Sponges Designed for use in Turtle Clean 30 External Canister Filters (formerly Turtle Clean 511) These fine mechanical sponges are easy to remove from your turtle's filter, rinse, and reuse again and again Zoo Med's Mechanical Filter Sponge is the first line of defense in removing dirt and floating debris from your terrarium or aquarium