CerMedia MarinePure 1.5-Inch Sphere Bio-Filter Media for Marine and Freshwater Aquariums, 2-Quart
Ceramic Bio-Filter Media with Vast Surface Area & Open-Flow Porosity. For ammonia & nitrite removal in fresh & marine aquariums. One MarinePure Sphere has the same surface area as 1,350 plastic bio-balls. Use in wet/dry filters, sumps or canister filters.