Marina Slim Filter “Zeo-Carb” Cartridges (3-pack) – A set of three replacement filter cartridges for Marina Slim power filters (like the S10, S15, or S20 models). Each cartridge contains a mix of zeolite and activated carbon, along with a floss pad. The zeolite helps remove toxic ammonia from the water, while the carbon eliminates discoloration and odors. Together, they keep the aquarium water clear and healthy. Replacing the cartridges monthly (or as needed) ensures your filter continues to perform optimally – this 3-pack provides a convenient supply so you can maintain high water quality with minimal effor