UV 5 and Mini UV Replacement UV Bulb (Tetra) Replacement UV5 Bulb for the Tetratec UV5 Sterilizer. Instructions: For optimum performance, replace the bulb every 12 months. Specifications: The dangerous ultraviolet radiation of this lamp is harmful to eyes and skin. Installations with these lamps are to be screened off completely. Size: 5 watts Info from the Aquarium guys