Coralife BioCube Mini UltraViolet SterilizerBioCube Mini UV Sterilizer low voltage ballast with 5W bulb aids in eliminating harmful parasites, bacteria and free-floating algae. Designed for attachment to the existing BioCube pump for easy set-up and use. Includes universal adaptor for use with other small aquariums. Ultraviolet sterilization is an effective method for controlling harmful micro-organisms such as bacteria and parasites that can build up within an aquarium. Water passes through the sterilizer where contaminants are neutralized via exposure to ultraviolet light. The result is consistently healthier and clearer aquarium water. Designed to fit inside the aquarium, the UV Sterilizer attached directly to the built-in BioCube pump for ease of setup and use. Universal adaptor also included, for use with other small aquariums.