Keep the water in your tank flowing in a natural manner with the Hydor Koralia 4-UL 1400-GPH Aquarium Circulation Pump. Using a patented magnetic support, this unique device is easy to install and stays securely in place. A sphere joint allows you to direct the flow of water as needed, and an anti-vibration system keeps it stable. This Hydor circulation pump has a 12-watt motor and moves up to 1,200 gallons per hour while using less energy than many other models. A built-in net prevents the entry of fish.