Feature:The Jebao 36W Ultraviolet Sterilizer is used to destroy single celled organisms such as water borne bacteria and viruses. The sterilizer is also used to control algae and and to kill fungi and protozoa. Aqua Ultraviolet Sterilizers are recommended for both fresh and salt water systems as well as ponds. The ultraviolet lamp emits a germicidal ray which alters or disrupts the DNA or RNA of targeted organisms such as algae, bacteria and protozoa. The Aqua ultraviolet sterilizer works better on filtered water. Any debris in the water can inhibit UV transmission. Instructions:The Jebao 36W Ultraviolet Sterilizer can be installed vertically or horizontally. The best place to install your UV sterilizer is after the filter. If it is necessary to install the sterilizer before the filter, adequate pre-filtration should be used to prevent the quartz sleeve from breaking from debris. If your system is installed after the filter and is properly sized, the water should be clear in 3-5 days. If it is installed before the filter, the water should be cleared in 7-10 days. The Jebao 36W Ultraviolet quartz sleeve may need to be cleaned to remove film from the surface that will hinder the effectiveness of the UV. It can be cleaned with swimming pool muratic acid, lime away or a similar product. Do not use any type of abrasive substance on the quartz sleeve as it may scratch the quartz.