What issue can arise from low total alkalinity in pool water?

Low total alkalinity in pool water can lead to a condition known as pH bounce. When total alkalinity is low, the water's ability to resist changes in pH is diminished. This instability can cause the pH level to fluctuate rapidly, making it challenging to maintain a balanced water chemistry. Such fluctuations can lead to discomfort for swimmers, damage to pool surfaces, and can hinder the effectiveness of sanitizers.

While pH bounce is a significant consequence of low total alkalinity, other options involve issues that are more typically related to high total alkalinity or different water balance problems. Therefore, the impact of pH bounce is a more direct and specific issue resulting from low total alkalinity, rather than the broader consequences described by the other potential answers.