What must the operator check in pool chemistry before bathers are admitted?

The requirement for checking chlorine or bromine residual and pH value before allowing bathers in the pool is essential in maintaining a safe swimming environment. Chlorine and bromine are disinfectants that kill harmful bacteria and other pathogens present in pool water. Ensuring that there is an adequate residual of these chemicals indicates that the water is being properly sanitized.

Additionally, monitoring the pH value is crucial because it affects both the comfort of the bathers and the effectiveness of the disinfectants. If the pH is too high or too low, it can irritate the skin and eyes of swimmers and reduce the effectiveness of the chlorine or bromine.

While checking free available chlorine and total chlorine residuals, the characteristic of water temperature, and the presence of contaminants and bacteria are all important aspects of pool management, the combination of chlorine or bromine levels with pH provides a fundamental assessment of water safety that is directly related to swimmer health and comfort.