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How to get rid of mustard algae?

What is mustard algae?

This algae is rare and persistent, but don’t worry; by following a few simple instructions, you can eliminate this microbial threat and prevent it from returning.

Frequently found in southern climates, and more rarely in northern ones, mustard algae is often mistaken for sand, dirt or a stain in your pool. They are members of the family of microbes known as xanthophytes and these algae are very resistant to chlorine.

In fact, mustard algae likes to attach to pool walls and other elements, which can cause problems as it stays alive outside your pool as well. This nasty little customer can also cling to pool equipment, toys, floats and even your swimsuits.

Removing Mustard Algae in a few steps

1. Wash your swimwear in the washer

Using a regular or color-safe bleach, as appropriate, can give you added peace of mind as it will kill mustard algae that clings to the fabric of your swimsuits.

2. Clean your pool toys, accessories, etc.

Using a clean cloth and a chlorine-based cleaner (never pure bleach), thoroughly clean all toys and other accessories that may come in contact with your pool water.

Why not just use bleach? Using pure bleach could damage some plastics and rubber items. So it’s best to stick with a multipurpose cleaner that will kill algae without destroying your belongings.

If you only have bleach on hand, dilute it in a solution of one part bleach to ten parts water before applying it to any surface.

3. Brush and vacuum the mustard algae.

Removing algae is the first step to a fully sanitized pool, and to do that, you need to start with a good scrub. Use a brush to loosen the algae stuck to the walls and make it easier to vacuum.

Note: mustard algae can live in your pool filter. Before vacuuming, put it on the « waste » setting, not « backwash. »

Finally, add fresh water to replace the water lost during vacuuming.

4. Test and balance your pool water

When you don’t have enough sanitizer or your water chemistry is out of whack, algae can grow extremely quickly. So test your pool water by taking test strips or come see us in store!

After taking a reading on your home test, adjust the alkalinity to between 100 and 150 ppm and the pH of your water to between 7.4 and 7.6. Properly balanced water will allow your shock treatment to work more efficiently!

How to properly collect a water sample: Click Here!

5. Brush your pool again

This will help suspend the algae. When they float freely in the water, the shock treatment will have a much easier time attacking and destroying them.

6. Shock Treatment

Like good old-fashioned green algae, mustard algae are susceptible to the cleansing power of shock treatments, especially in high concentrations.

Add Dazzle Ultra Shock or Pristiva Premium Shock (for salt pool). Add all the contents slowly into the skimmer or spread it slowly and evenly over the pool surface. Brush the pool surfaces immediately after application to ensure the product is fully dissolved. Wait at least one hour, then apply Dazzle Algae Clear 60.

Apply Dazzle Algae Clear 60 by pouring it over the water along the edges of the pool. Brush pool surfaces regularly to help dislodge clinging algae and better distribute the product.

7. To speed up the removal process

Add Mineraluxe Advance Sticksby removing the packaging and placing them in the skimmer basket with the pump running. Dissolving time is approximately 20 minutes, but may vary depending on water temperature and flow rates. This mineral-based product is excellent for freeing pool surfaces of biofilm and other growth. It will further help speed up the resolution of the problem.

**If you have a salt pool please use Pristiva Primer

8. Continue to rock the pool and brush the walls

Brush the bottom and sides of your pool as often as possible. This will prevent mustard algae from clinging to your pool and keep it in suspension for faster annihilation.

Adjust your chlorine levels as necessary to maintain its high killing power. Be sure to test your pH and alkalinity levels frequently, and adjust them as necessary to keep them in the optimal ranges.

9. Test and confirm that your pool is free of algae

After the last Shock treatment, test your water chemistry. If the balance is right and the water looks clear, congratulations, it’s successful! 

After an algae infestation, it’s a good idea to thoroughly clean the pool filter and its filter media to remove all residual algae and organic matter (scale and other debris). Use Dazzle Rapid Action Filter Cleanse or Jack’s magic super Pacs to restore the cleanliness and efficiency of your filtering environment.

10. How to prevent mustard algae from growing again

  1. Smart Water Chemistry: Keep your pH, alkalinity and sanitizer levels in the right ranges at all times.
  2. Stick to a schedule: Run your pump and filter non-stop, all season long. Keep your pool clean by brushing and vacuuming regularly.
  3. Shock! Depending on the maintenance program you use, remember to shock your pool at dusk or in the evening:
    • Pure Wow System: Amaze or AmazePlus once a week
    • Mineraluxe System: Oxygen once a week or every other week depending on how much water
    • Pristiva System (salt pool): Premium Shock once a month
  4. Clean everything: if they stay wet and dirty, pool toys, floats, ladders, steps, diving boards, slides, and sun covers can all harbor algae. A quick splash of water and a wipe down with a cleaner like Clean and Perfect or the Jack’s Magic tile cleaner will go a long way in protecting you and your pool from algae.