Aquatop SP9-UV Submersible UV Filter Sterilizer Pump, 9W, 264 GPH, for Aquariums up to 100 GallonsThe Aquatop SP9 UV submersible UV filter is a new and innovative method for eradicating and controlling floating algae. Unlike typical UV clarifying systems the SP9 UV requires no special plumbing and is easy to use and maintain. Simply place the SP9 UV directly into your tank or sump system up to the waterline. The built in pump will draw water in running it past the 9 watt UV bulb. The UV light will clean and clarify producing crystal clear water.