The Reef Sump is designed with the unique requirements of saltwater and reef aquariums in mind. Each large capacity sump includes a cover, square foam, 1 in. bulkhead, 3 ft. of 1 in. flex hose, and a 300 micron bag for excellent prefiltration. Plenty of sump space makes adding a protein skimmer or other aquarium accessory simple and easy, while the extra water capacity helps keep your main tank stable.