Shop › Petworx External Canister Filter 800L/H Image 1 of 1 Petworx External Canister Filter 800L/H $110.00 Sold Out Petworx External Canister Filter 800L/H. Suitable for fresh water or saltwater aquariums. Sold Out Added! Petworx External Canister Filter 800L/H. Suitable for fresh water or saltwater aquariums.