Discovering that your swimming pool has turned green can be frustrating, especially during the swimming season.

In most cases, green pool water indicates algae growth. Algae can develop when chlorine levels fall too low, water circulation becomes inadequate, or the pool is not receiving consistent maintenance. Hot weather, heavy rainfall, and increased swimming activity can contribute to these conditions.

How Do You Clear a Green Pool?

• The first step is identifying the underlying problem.
• Start by testing the pool water to determine chlorine and pH levels. Check that the pump and filtration system are operating correctly.
• Remove leaves and debris, then thoroughly brush the walls, steps, and floor to loosen algae attached to the pool surfaces.
• Next, apply an appropriate amount of chlorine shock or algae treatment based on accurate water testing, pool volume, and product directions.
• The filtration system must continue to run in order to remove suspended algae and contaminants. Filter cleaning, repeated brushing, and addition of appropriate chlorine shock may be necessary until the water becomes clear.

Why Does My Pool Keep Turning Green?

• Recurring algae problems may indicate an underlying issue, such as inadequate chlorine, poor circulation, excessive stabilizer, or improperly maintained filtration equipment.
• Occasionally, clear water with a green tint may result from dissolved metals rather than algae, making accurate diagnosis important. In this case, a metal-sequestering agent can be used to remove the metal from the water.
• The best way to prevent a green pool is through consistent water testing, proper chemical balancing, and regular cleaning.
• Avoid swimming until the water is clear and sanitizer levels are appropriate.