Highly Efficient Cleaning: hygger aquarium U-V light adopts a 254nm wavelength to effectively clean green water. Turning cloudy green water into crystal clear clarity. It is a good choice for freshwater and saltwater aquariums to clean water. U-V Light Shielded Housing: hygger water clean lamp adopt closed plastic ring and tight structure, which makes the U-V cannot travel through the protective casing, ensures no lighting escape, protecting both fish and humans. The housing features a convenient viewing window, allowing you to check the lamp's working status safely and effortlessly. 4 Modes Timing and Memory: With a simple press of the power switch, you can select a timer setting of 3H, 6H, 12H, 24H to suit your needs. The light will then automatically manage the on/off cycle, with settings remembered for your convenience. Usage Method: Our fish tank clean water lamp can be connected to a external canister filter, or to a sump bump system in fish tank or connected to the bottom filter. In conclusion, connections need to be made between the hoses. It can be used both inside and outside the fish tank. Package Contains: 1 U-V light for aquarium, 2 stainless steel clamp, 3 pairs of connector fitting (13mm/16mm/19mm) and 1 user manual. NOTE: Do not use the product directly in the fish tank, especially the HG250-5W. The product needs to be connected to hose and used in conjunction with a filter bucket or bottom filter or water pump. It mainly achieves the purpose of cleaning water through the circulation of water flow Aquarium Clean Light