Hozelock. Fish mate: Pond replacement filter lamp, uvc lamps should be changed every 8 to 12 months as they lose strength, The light emitted by these lamps is harmful to both skin and eyes and must only be used in enclosed fittings that prevent the light from escaping. Installations with these lamps are to be screened off completely. Disinfection of drinking water. Instant-Start Germicidal Lamp. This is a UV replacement fluorescent light bulb, which are germ killing fluorescent UV lamps. They are used in disinfection of municipal wastewater, industrial process of water and primary drinking water, as well as in the disinfection of air and HVAC systems. Additional applications include food and beverage processing, as well as ink curing applications, wherever killing of airborne germs is needed.