When using water evaporation as a means of cooling air, a portion of the water is removed while leaving behind everything else that is within the water source. Overtime the concentration of these other things can build up and reduce efficiencies or damage evaporative cooling equipment. Much of which is seen as scale deposits, corrosion, or microbiological growth. Using UV light and filtration is a very effective method for controlling microbial growth and particulate buildup of a bulk water source. Continuous treatment of the water source is imperative for long term operation of evaporative cooling systems.