The Oceanic BioCube features high-quality components and can be used for saltwater or freshwater setups. Enhanced filtration system features dual filter intakes to draw aquarium water from the surface and mid-water for improved water circulation and filtration. Replaceable 2-stage filter cartridge provides easy-to-maintain mechanical and chemical filtration. Bio-ball wet/dry filtration system improves gas exchange and provides efficient biological filtration. Viewing window for filtration water pump to ensure optimum performance. UL-Listed submersible pumps.