Mustard Algae



Mustard algae is a yellowish green colour. Mustard algae in its early stages can look like small patches of sand or pollen on the bottom of the pool. It brushes away very easily, but comes back quickly. In more extreme cases, it can turn the entire pool a pea-green colour.

Mustard algae is a resistant strain and easily reinfests the pool through bathing suits, automatic cleaners, nets, poles, brushes, and other equipment that was used in the pool while the algae was present. It is important to chemically clean all of your equipment with a solution of chlorine and water while you are treating for the algae in the pool. Wash bathing suits with detergent, and bleach if possible, before wearing them in the pool again.

To prevent problems with algae in the future, use Optimiser and your maintenance algae inhibitor regularly.

To kill mustard algae:

  1. Chemically clean the filter with Filter Brite according to label instructions for your filter type and size.
  2. Perform a water analysis and balance according to ALEX recommendations.
  3. Add 1 bag of Burn Out Extreme per 50,000 litres via the skimmer or 150 grams of Burn Out 35 per 10,000 litres directly to the pool with the pump running.
  4. Circulate for at least 1 hour. If you have shocked the pool within the last 12 hours, skip this step.
  5. Dilute 100 mL of MSA II Algaecide per 10,000 litres in at least 10 litres of water in a clean plastic bucket.
  6. Pour this dilution directly in front of the returns.
  7. 72 hours after the addition of MSA II, check the water for copper. If any is present, use Pool Magnet according to label instructions to prevent staining.
  8. Do not swim until the chlorine or bromine residual drops to 5.0 ppm or less.

MSA II can be used to clean up both green and mustard algae growths, separately or in combination. One application will usually take care of both.

CAUTION: Do NOT use MSA II in biguanide pools. If the pool has an ioniser, check with the manufacturer before using this product. MSA II contains copper and some manufacturers will void the warranty on the ioniser if copper-based products are used.