Features: 1.APPLICABLE: Fish tank filter pad is suitable for use in saltwater, freshwater and aquariums and can be freely cut to size. 2.EFFECTIVE CLEANING: Fish tank biochemical filter pad can decompose excrement and feed residues, improve water quality, filter and clean well, and reduce fish mortality. 3.GOOD CONDITIONS: The dense pore space and softness of the aquarium filter pad meet the conditions for the cultivation of nitrifying bacteria. 4.CONVENIENT TO USE: Aquarium biochemical filter pad is non clogging and non deforming. Biocotton needs to be cleaned once a month and can be reused afterwards. 5.WIDE USAGE: The fish tank filter pad also provide mechanical filtration in aquaponics systems, turtle tanks, terrariums, and much more. Specification: Item Type: Fish Tank Filter Pad Material: Biochemical Cotton Size: Length: Approx. 38 cm/15.0in Width: Approx. 12 cm/4.7in Thickness: Approx. 2 cm/0.8in Use: Fish Tank, Aquarium Filtration PackageList: 6 x FishTankFilterPad Note Manual measurement please allow some errors.