What is the maximum recommended level of combined chlorine?

The maximum recommended level of combined chlorine is 0.5 ppm. Combined chlorine includes chloramines, which are formed when chlorine reacts with organic matter in the water, such as sweat, urine, and other contaminants. High levels of combined chlorine can create unpleasant odors, irritate the eyes and skin of swimmers, and indicate poor water quality.

Keeping the combined chlorine level at or below 0.5 ppm helps ensure that the pool remains safe and comfortable for users. Levels higher than this threshold suggest that the effective disinfecting properties of free chlorine are being decreased by the formation of chloramines, warranting further action such as shock treatment to restore water quality. This recommendation aligns with public health guidelines aimed at maintaining optimal swimming conditions and ensuring the safety and enjoyment of all swimmers.