UV energy is found in the electromagnetic spectrum between visible light and X-rayand can be best described as invisible radiation. UV system consists of low pressure mercury Discharge lamp which is made of special quartz glass envelope material and with filled with an inert gas, which delivers a constant high intercity light. High does of ultraviolet light energy at a wavelength of 254 nanometers destroy pathogenic microbes by affecting DNA in the cell, disabling their reproductive process. UV energy adds nothing nothing to the water nor dose it generated any by products. Water chemistry dose not change.