The Tetra Whisper Power Filter for aquariums offers quiet 3-stage filtration for clean water and healthy fish. Dual-sided mesh catches debris and fish waste in its dense fibrous network then Ultra-Activated carbon provides chemical filtration by absorbing odors and discoloration. This filter uses easy-to-change Tetra Whisper Bio-Bag Cartridges (size large) which trap particles floating in your aquarium. The Tetra Whisper Power Filter 40 treats aquariums up to 40 gallons (210 GPH).