Fluval FX Series Filter Pad Replacements are designed to maintain optimal filtration performance in FX2, FX4, FX5, and FX6 canister filters. These pads provide mechanical, chemical, and biological filtration to keep aquarium water clean, clear, and healthy for your fish and plants. Each type of pad targets specific needs, from removing debris and polishing water to absorbing nitrites, phosphates, and dissolved chemicals. They are easy to install and replace, ensuring your filter continues to operate at peak efficiency.