What effect does algae have on pool water quality?

Algae plays a significant role in diminishing pool water quality, primarily by lowering the effectiveness of chemicals used to maintain the water. When algae bloom occurs, it competes with disinfectants, such as chlorine, for the available free sanitizer in the water. This competition reduces the amount of chlorine available for keeping germs and bacteria in check, making it harder to ensure that the pool water remains safe and sanitized.

Moreover, the presence of algae can lead to the formation of additional compounds, which can create difficulties in achieving balanced water chemistry. With reduced chemical effectiveness, the risk of waterborne illnesses and cloudy water increases, necessitating more frequent and intense treatments to manage the problem effectively.

While the other options suggest positive or negligible effects of algae on pool water, the reality is that algae's presence is detrimental and requires prompt management to restore water quality.