JW Pet Company Fusion 3 Power Filter for 10-29 Gallon Aquariums Aquarium Filter Quiet, efficient and simple to clean Utilizes simple drop-in cartridges FUSION Floss Cartridge, FUSION Ceramics Modules and FUSION Activated Carbon Bags It is time to change the FUSION Floss Cartridge when the Yellow Ball rises above the Yellow Line it's that simple Suitable for 10 to 29 gallon aquariums 100 g.p.h. Bright ideas for better fish keeping!