The RC9 provides the function of advanced measure and control of your sanitiser and pH levels. pH is a measure of the balance of acids and alkaline. Perfect pH means active sanitiser, and active sanitiser means lower usage of the sanitiser, saving you money. By constantly measuring and dosing pH adjuster to maintain the correct set point, the RC9 controller ensures the sanitiser in your water is maintained at its optimal level.The RolaChem 9 series provides combined sanitiser and pH adjuster management of your pool or spa so that it always looks great and is safe and healthy to swim in. With sophisticated sensors and software programming the sanitiser and pH levels are continuously monitored and adjusted to your swimming pool or spas requirements, weather conditions or bather load. All while dramatically reducing the maintenance required for your pool and spa.