The Marineland Maxi-Jet Multi-Use Water Pump acts as three pumps in one – power head, utility pump and circulation pump – to power under-gravel filters, protein skimmers, calcium reactors and refugiums, as well as run small fountains. This multi-use water pump and power head includes a conversion kit to turn the power head into a prop-style circulation pump. Venturi pump allows for fully adjustable aeration. Select the proper size pump for your tank. Available in four sizes: 400 (110 to 500 GPH); 600 (160 to 750 GPH); 900 (230 to 1000 GPH); and 1200 (295 to 1300 GPH).Marineland aquarium pumps provide powerful, dependable water circulation and aeration. Versatile and easy-to-use, Marineland pumps are available in a range of sizes to handle the water flow and oxygenation needs of aquariums at rates of 100 to 1300 GPH.