COLOURFUL AQUARIUM - High Quality Aquarium Sponge for Top Filters | 3 Feet | Washable Aquarium Sponge - Filter MaterialBiochemical Sponge / Cotton Filter for Salt & Fresh Water Fish TankMain Features: 1. This product can be used for sea water tank, fresh water tank, and water weeds tank with the sizes being cut as your wish. 2. According to the analysis of the experts, products with this pore gap and flexibility and the most suitable breeding grounds for cultivating the fine nitro bacteria. 3.The filter cotton has the best effect on decomposing the excrement and the forage leftover, and improving the filtering and cleaning of water, it can reduce the death rate of fish. 4. Being cleaned with water once per month , without blocking and deforming, it can be used again after cleaning and can be repeated for use. 5. Color : White Sponge 6. The filter cotton Size:(L x W x H) 100cm x 13.5cm x 3cm. 7.Item Component: One Sponge