 To minimize exposure to pathogens, swimmers should avoid getting water into their mouths and never swallow pool or spa water.Maintaining an effective concentration of disinfectant is critically important in assuring the safety and health of swimming pool and spa users.When any of these pool chemicals are used, it is very important to keep the pH of the pool in the range 7.2 to 7.8 – according to the Langelier Saturation Index, or 7.8 to 8.2 – according to the Hamilton Index; higher pH drastically reduces the sanitizing power of the chlorine due to reduced oxidation-reduction potential (ORP), while lower pH causes bather discomfort, especially to the eyes.