How Do You Remove Mustard Algae?

Remove mustard algae from a swimming pool by vacuuming the pool, adjusting the pH, adding pool shock, and brushing the sides and walls of the pool. Clean all pool toys and bathing suits so you do not reintroduce the algae to the pool.

  1. Vacuum the pool

    Fill the pool with water, set the vacuum to waste, and vacuum the walls and floors. Do not set the vacuum to backwash.

  2. Adjust the pH

    Use a pH kit to test the pH of the water. Look for a kit that provides immediate test results. If the pH is below 7.4 or above 7.6, add the appropriate chemicals to adjust so it is within this range. Adjust the alkalinity to between 120 and 150 parts per million.

  3. Add the pool shock product

    Put on thick rubber gloves. Mix the appropriate amount of pool shock for the size of the pool in a 5-gallon bucket filled with water. Use a stick to stir the product until it dissolves. Pour the liquid into the pool. Pour it along the sides and toward the middle of the pool. For best results, shock the pool at night.

  4. Brush the sides and floor

    Use a long-handled pool brush to continue to brush the pool sides and floor the next several days to loosen the mustard algae. Leave the tools in the pool so the shock disinfects them while they are not in use.