The 13 watt Ista UV Sterilizer Submersible Filter Pump is a top of the line water filter that is well suited for both freshwater and saltwater applications. The durable, 2 in 1 design acts as a protective barrier for your tank, helping to keep aquarium water crystal clear by eliminating harmful buildups of bacteria, algae and various parasites. Completely safe for all inhabitants of your tank, the sterilizer does not impact the beneficial bacteria that lives on gravel, rocks and wood, but only targets the harmful bacteria that floats throughout the water. The sleek and slender filter pump is fitted with an electrical ballast to ensure proper currents and functions, and can be positioned so that it does not become the main visual attraction within the tank. Water is directed into the unit via 8 separate detours and in the event that the UV light becomes damaged or disconnected, the Ista UV Sterilizer Submersible Filter Pump will begin beeping loudly to alert you of the issue. The device is suitable for tanks up to 53 gallons.