General Discussion

The timing—just days after the pool was refilled—has prompted debate over whether the darker coating could be playing a role.

Darker surfaces absorb more sunlight and heat than lighter ones, which in shallow water can raise temperatures and increase the energy available for algae growth—potentially accelerating reproduction rates.

Lowe said this effect could be significant, as darker surfaces effectively act as a heat source. "The darker an object the more light it absorbs and the warmer it gets," he said, adding that this can create "perfect conditions for algae to bloom" in shallow, sunlit water.