What characteristic of pool water can be affected by low pH, leading to swimmer discomfort?

Low pH in pool water can lead to increased acidity, which directly affects swimmer comfort by causing skin irritation. When the pH level falls below the ideal range (typically 7.2 to 7.8), it can disrupt the natural protective barrier of the skin and increase the likelihood of irritation. Swimmers often experience redness, itching, and discomfort due to the acidic conditions. Maintaining proper pH levels is crucial not just for comfort but also for overall water quality, as it can impact the effectiveness of sanitizing chemicals and the longevity of pool surfaces.

Regarding the other characteristics, while transparency, temperature, and alkalinity are important aspects of pool water chemistry, they are not directly related to immediate discomfort experienced by swimmers in the same way that low pH can cause skin irritation. Transparency can be affected by various factors, including load and filtration, temperature is usually a separate concern, and alkalinity, while influential in buffering pH changes, does not specifically relate to direct discomfort.