What does a high total chlorine reading indicate about pool water?

A high total chlorine reading indicates the presence of combined chlorine in the pool water. Total chlorine is the sum of both free chlorine (the amount available to disinfect) and combined chlorine (chlorine that has reacted with contaminants such as sweat, urine, and other organic matter). When the total chlorine level is elevated, it suggests that there is a significant amount of combined chlorine, which means that the chlorine is being used up to neutralize these contaminants rather than being available for effective sanitation.

High levels of combined chlorine can lead to water quality issues, such as unpleasant odors and irritation to the eyes and skin for swimmers. It is generally recommended to maintain a proper balance of free chlorine to ensure a safe and sanitary swimming environment. When combined chlorine levels are high, pool operators should consider "shocking" the pool, which involves adding a large dose of chlorine to break down the combined chlorine and restore effective sanitation.