What is the best method to determine if additional chlorine is needed in a pool?

The best method to determine if additional chlorine is needed in a pool is to check the chlorine and pH levels. Chlorine is essential for maintaining safe and sanitary water conditions in the pool, effectively killing bacteria and other harmful pathogens. Regular testing of both chlorine and pH levels gives a clear indication of the pool’s water quality.

If the chlorine levels are too low, it signals that the water is not adequately sanitized, which can lead to health risks for swimmers. Testing the pH level is equally important because chlorine's effectiveness is heavily influenced by the pH level of the water. An improper pH level can reduce chlorine's ability to kill germs and maintain clarity, meaning even if there is chlorine present, it might not be effective. Therefore, consistent monitoring of these two parameters ensures that the pool remains safe and clean for all users.

In contrast, while a visual inspection can provide some insight into the pool's appearance, it won't accurately measure the chemical balance necessary for effective disinfection. Assessing air temperature relates to comfort and evaporation but does not inform about the pool's sanitation needs. Testing for water hardness is important for maintaining proper water balance and surface care but does not directly impact the necessity of chlorine levels in the pool.