What is the recommended chlorine residual in swimming pools?

The recommended chlorine residual for swimming pools is 1.0 to 1.5 parts per million (ppm). This range is considered optimal for effective disinfection and keeping the water safe for swimmers. Chlorine serves as a sanitizer that helps to eliminate harmful microorganisms and pathogens that can thrive in pool water. Maintaining the residual within this range balances effective disinfection, user comfort, and the potential for chlorine-related irritants.

Maintaining a chlorine level within this range ensures that the water is adequately sanitized without causing discomfort, such as skin or eye irritation, that can occur if the levels are too high. Additionally, it helps in controlling the formation of disinfection byproducts that can arise when chlorine reacts with organic matter in the water. Thus, a chlorine residual of 1.0 to 1.5 ppm strikes the right balance to protect public health while providing a comfortable swimming experience.