JBL UV-C Tube LampUV C water clarifier replacement bulbs from JBL, designed for the JBL UV sterilizer systems which can be purchased here. Bulbs are recommended to be replaced every 6 to 12 months. Key Features: Crystal clear and healthy water: UV C water clarifier for the quick and efficient elimination of greenish and whitish cloudiness in aquariums. No change of water values, no effect on cleansing bacteria and water parameters. Germ killing UVC radiation of 255nm,