Create a healthy and clean environment for your turtle with the Marineland Foam Refill for C Series Filters. With these foam refills, aquarium water is able to be drawn into the canister and through your stacked media trays for amazing filtration. Once the water returns to your turtle’s tank, it is sparkling and clean. Maintaining the C Series Filters is easy, too. Simply push the lever, turn the key, and lift out the easy to access media trays.