The Aquatop SP13-UV submersible UV sterilizing pump (395-GPH) is a new and innovative method for eradicating and controlling free-floating micro-organisms as well as disease causing pathogens. Unlike typical UV sterilizing systems, the SP13-UV requires no special plumbing and is easy to use and maintain. Simply place the SP13-UV directly into your tank or sump system up to the waterline. The built in pump will draw water in, running it past the 13 watt UV bulb. The UV light will sterilize and clarify, producing crystal clear water.