Fluval FX Series Polishing Pads are ultra-fine filter pads designed for use with FX2, FX4, and FX6 canister filters. They capture the smallest particles and impurities to produce crystal-clear water, enhancing water quality and clarity in both freshwater and marine aquariums. Ideal as the final stage of filtration, these pads help polish the water by removing debris that mechanical and biological media may miss. Regular replacement ensures consistent filtration efficiency and pristine aquarium conditions.