Protecting swimmers and their families from recreational water illnesses (RWIs) is the reason that pool staff regularly check both chlorine and pH levels. Chlorine and pH, your disinfection team, are the first defense against germs that can make swimmers sick.
Chlorine kills germs in pools–but it takes time to work. Therefore, it’s important to make sure chlorine levels are always at the levels recommended by the health department (usually between 1.0 – 3.0 ppm).
All sorts of things can reduce chlorine levels in pool water. Some examples are sunlight, dirt, debris, and material from swimmers’ bodies. That’s why chlorine levels must be routinely measured. However, the time it takes for chlorine to work is also affected by the other member of the disinfection team, pH.