Marina 360 & Splash Replacement Filter Cartridges. The Marina 360 & Marina Splash Replacement Filter Cartridge, with carbon and zeolite, improves water clarity and color while removing pollutants and odors. This replacement filter cartridge is designed for use with the Marina 360 Aquarium and the Marina Splash Aquarium. The Marina 360 & Marina Splash Replacement Filter Cartridge comes in a package of 4. With carbon and zeolite for clean and clear water Removes pollutants and odors For use with Marina 360 and Marina Splash aquariums For best results, replace 1 cartridge every 2-4 weeks Available Size: 4-Pack