If there are complaints of red eyes in swimmers and chlorine odors are present, what should the pool operator do?

When swimmers complain of red eyes and chlorine odors are present, it indicates a potential issue with chloramines in the water. Chloramines are formed when chlorine combines with organic matter, such as sweat, urine, and other contaminants. These compounds can cause irritation to swimmers and produce a strong chlorine smell.

Shocking the pool with chlorine helps to break down these chloramines and restore proper water quality by essentially “shocking” the system with a high dose of chlorine. This process increases the chlorine level temporarily, which allows it to effectively oxidize the chloramines and other organic matter, improving overall sanitation and clarity of the water. Removing the buildup of chloramines is crucial for ensuring swimmer comfort and safety.

The other options, while valuable for different water balance adjustments, do not address the issue of chloramines directly. Calcium chloride is typically used to increase calcium hardness, soda ash is used to raise pH levels, and sodium bicarbonate is used to increase alkalinity. None of these substances tackles the presence of chloramines or effectively eliminates the chlorine odor associated with them, making shocking the pool with chlorine the most appropriate response in this situation.