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How to Get Green Algae-Type Stuff Off a Concrete Pool

Green algae are the most common yet simplest algae type to remove from your swimming pool. When algae grow in concrete in-ground pools, they stick to pool walls and continue to grow while turning your water green if left untreated. The earlier you attack algae the easier it is to clean. Removing algae from your concrete pool involves cleaning your filter, adding shock and doing a lot of brushing.

Things You'll Need

  • Test strips
  • Nylon pool brush
  • Chlorine shock
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Instructions

    • 1

      Backwash your pool filter and clean it thoroughly before adding chemicals. The process of backwashing differs, based on whether you own a sand, diatomaceous earth or cartridge filter. When you're finished, turn on the filter and run it continuously for at least 24 hours.

    • 2

      Test the pool water chemistry and balance the pH and alkalinity levels as needed. As a pool owner, you should have chemicals on hand for increasing and decreasing pH and alkalinity. Adjust as indicated on the testing strips. Dosages can vary widely based on readings.

    • 3

      Add 1 lb. of diluted granular shock for every 7,000 gallons of pool water. Broadcast it evenly over the surface of the water and run the filter for 24 hours. Shock will begin to clear the water and kill the green algae.

    • 4

      Scrub the pool walls with a nylon pool brush. After shocking the pool, the algae will rub off more easily. Continue running the filter and backwash again after brushing. Test the chlorine levels in the pool. Maintain an active amount of sanitizer (chlorine) in your pool to continue killing algae. You may have to brush several times over the course of a few days before the algae are completely eliminated