
Why Does My Pool Water Turn Green?
Few things are more frustrating than walking outside and seeing your crystal-clear pool water suddenly turn green. But don’t worry there’s a science behind it, and it’s something we deal with all the time here in Texas! The Culprit: Green Algae In our hot and sunny climate, several types of green algae thrive in swimming pools: Chlorella → microscopic algae that can turn water cloudy green within a single day if chlorine drops. Scenedesmus → often appears as floating green patches and can spread across the pool surface overnight. Euglena → gives water a deep green tint and grows quickly in stagnant or under-circulated areas. These algae can multiply fast in warm Texas water, some species can double in just 3–6 hours if not controlled. The Chemistry: Chlorine Balance Chlorine is your pool’s best friend, it kills bacteria and prevents algae. But when chlorine levels fall too low, or when


