The Ceramic Filter Media provides a high surface area for beneficial bacteria to colonize. These bacteria effectively breakdown debris and waste particles which ultimately results in cleaner, healthier water for your aquarium inhabitants. It is best to only replace the ceramic filter media when you do a complete tank restart as to not disturb the beneficial biological load. Ceramic Filter Media is replacement media for the FiltoSmart Filter series. Includes 14.8 oz. of ceramic filter media. Ceramic Filter Media provides a high surface area for beneficial bacteria to colonize. Beneficial bacteria effectively breakdown debris and waste particles which ultimately results in cleaner, healthier water for your aquarium inhabitants. Replace your ceramic filter media only when completing a complete tank restart as to not disturb the beneficial biological load Ceramic filter media is replacement media for the FiltoSmart 60, FiltoSmart 100, FiltoSmart Thermo 100, FiltoSmart 200, FiltoSmart Thermo 200, FiltoSmart 300, and FiltoSmart Thermo 300