Evaporative cooling is the most energy efficient cooling method, but it also requires a high degree of maintenance in addition to water consumption. The most common problem with evaporative equipment is poor water treatment. By offering effective and easy water treatment much of that maintenance downside of evaporative cooling can be minimized. Water treatment must manage three problems: scale, corrosion, and biological growth. This paper will discuss the causes of these problems and two solutions: chemical water treatment or chemical-free treatment systems.