Fluval FX4 External Canister Filter (1000 Litres)Recognized as the workhorse of canisters for their legendary strength and durability, high output FX Series filters sweep the tank harder and faster to retain a greater amount of debris. Combining patented SMART PUMP performance optimizing technology with auto start stop operation and intricate multi stage cleaning featuring an expansive basket in basket media tray design, FX owners will spend more time enjoying their aquarium, and less time