How To Get Rid Of Mustard Algae? Tips From Our Pool Experts

Cleaning, Swimming Pool Tips

By Miami Pool Company

Discovering mustard algae in your pool can be a disheartening experience. Known for its stubborn nature and resistance to typical chlorine levels, mustard algae is a nuisance that requires specific tactics to eradicate.

If you’re wondering how to get rid of mustard algae, you’ve come to the right place. Our pool experts are here to share their knowledge and tips to help you reclaim the clarity and health of your pool water.

What Is Mustard Algae?

Mustard algae, or yellow algae, is a chlorine-resistant form of green algae that appears as yellow or brown patches on pool walls and floors, particularly in shaded areas. Unlike its green counterpart, mustard algae clings tightly to pool surfaces and can be challenging to remove.

Guide On How To Get Rid Of Mustard Algae

Mustard algae, with its stubborn nature and resistance to standard pool treatments, can turn pool maintenance into a daunting task. But fear not, for with the right approach, getting rid of this pesky intruder is entirely within your reach. Follow this step-by-step guide on how to remove mustard algae to restore your pool to its former glory.

Brush the Pool

Begin your battle against mustard algae by arming yourself with a sturdy pool brush. Attack every inch of your pool’s walls and floor, focusing your efforts on loosening the algae’s grip.

Pay extra attention to shaded areas, corners, and crevices, as these are mustard algae’s favorite hideouts. The goal here is to disturb the algae, making it easier to remove in the subsequent steps.

Vacuum the Pool

Once you’ve given the algae a thorough brushing, it’s time to vacuum. Removing the dislodged algae is crucial to prevent it from settling back down or spreading. When vacuuming, opt to waste, bypassing the filter system.

This ensures that the algae are expelled from the pool environment entirely, rather than circulating back into the water.

Shock Your Swimming Pool

Mustard algae won’t go down without a fight, requiring a more potent shock treatment than you might use for regular pool maintenance.

Arm yourself with a high-dose chlorine-based shock and distribute it evenly across the pool, ensuring the pump is running to facilitate even distribution. This step is essential for killing off the algae and disinfecting the water.

Brush and Vacuum Again

After the shock has had time to work its magic (usually overnight), it’s time to brush and vacuum once more. This second round helps remove any lingering algae and ensures that your shock treatment reaches every nook and cranny where algae might hide.


Sometimes, despite our best efforts, pool maintenance challenges can surpass our expertise or available time. For those in Miami and nearby cities, our professional pool cleaning services offer peace of mind, ensuring your pool remains in top condition all year round.

Our experts are equipped to handle everything from routine maintenance to complex algae treatment, allowing you to enjoy your pool without the hassle. Call us today!


Post-Treatment Best Practices for a Mustard Algae-Free Pool

Victory over mustard algae in your pool is a significant achievement, but the battle doesn’t end with the last traces of algae. To ensure long-term success and prevent the unwelcome guest from making a comeback, adhere to these post-treatment best practices that will keep your pool pristine, inviting, and algae-free.

Conduct a Comprehensive Water Chemistry Check

The aftermath of an algae outbreak is the perfect time to reassess your pool’s water chemistry. Achieving and maintaining the ideal balance is crucial for preventing future algae growth.

  • pH Levels: Aim to maintain a pH level between 7.2 and 7.6. This range is optimal for sanitizer efficiency and minimizes the risk of algae and bacteria proliferation.
  • Alkalinity: Ensure your pool’s alkalinity falls between 80 and 120 ppm, providing a stable pH environment and further discouraging algae growth.
  • Chlorine Levels: While mustard algae is resistant to chlorine, maintaining a proper sanitizer level (1-3 ppm for chlorine) is essential for killing any remaining algae spores and safeguarding against new infestations.

Regular testing, ideally weekly, helps catch and correct any deviations before they become problems. Consider using a professional-grade test kit for accurate results.

Thoroughly Clean Pool Accessories, Toys, and Swimwear

Mustard algae are notorious for its clingy nature, adhering to almost anything that has been in the pool. Items such as pool brushes, toys, and even swimwear can harbor algae spores, risking recontamination.

  • Disinfecting Protocol: Soak all pool-related accessories and toys in a chlorine solution (follow manufacturer guidelines for the correct dilution rates) before allowing them back in the pool.
  • Swimwear: Wash swimwear that has been in the infected pool with hot water and detergent. A soak in a mild chlorine solution can offer additional peace of mind.

Filter Maintenance: The Key to Sustained Clarity

Your pool’s filter system plays a pivotal role in capturing and removing microscopic algae spores from the water. Post-algae outbreak, giving your filter system some TLC can significantly impact your pool’s overall health and clarity.

  • Cartridge Filters: Clean the cartridges thoroughly with a filter cleaner or replace them if they show signs of wear or damage.
  • Sand Filters: Perform a backwash followed by a rinse. For persistent algae issues, replacing the sand might be necessary.
  • Diatomaceous Earth (DE) Filters: After backwashing, add fresh DE powder to ensure the filter maintains its effectiveness.

Challenges of Removing Mustard Algae: What Not to Do

Successfully eliminating mustard algae from your pool is a testament to diligent maintenance and understanding the enemy. However, even the most seasoned pool owners can inadvertently make mistakes that compromise their victory over algae. Here’s an expanded look into the critical “don’ts” when tackling mustard algae, ensuring your efforts are effective and enduring.

Don’t Ignore Water Chemistry

The chemistry of your pool water is a delicate balance, and overlooking this aspect can sabotage even the most thorough cleaning efforts. Mustard algae, in particular, thrives in imbalanced water conditions.

  • Regular Testing: Ignoring the need for regular testing of pH, alkalinity, and sanitizer levels can create an environment where mustard algae not only survives but flourishes. Consistent monitoring helps catch imbalances early, preventing algae from gaining a foothold.
  • Proactive Adjustments: Failing to adjust your water chemistry proactively can give mustard algae the advantage. Immediate corrections ensure the water remains hostile to algae growth and supportive of swimmer comfort and pool equipment longevity.

Don’t Skip Steps

The process of eradicating mustard algae is methodical for a reason. Each step, from initial brushing to the final shock treatment, plays a critical role in ensuring complete algae removal.

  • Thorough Cleaning: Bypassing the initial brushing or vacuuming to waste can leave algae spores clinging to surfaces or circulating back into the pool, setting the stage for a swift comeback.
  • Adequate Shocking: Underestimating the amount of shock needed or skipping the post-shock brushing and vacuuming can mean surviving algae spores, ready to bloom anew. Ensure every step is followed diligently for a truly algae-free pool.

Don’t Underestimate Mustard Algae

Mustard algae’s resilience is often underestimated. Its ability to withstand typical chlorine levels and adhere to pool surfaces and accessories makes it a formidable opponent.

  • Overconfidence: Believing a single treatment or half-hearted cleaning will suffice can lead to frustration as mustard algae quickly reestablishes itself. Respect the tenacity of mustard algae and prepare for a thorough battle.
  • Complacency: Even after the algae seem to be gone, remaining vigilant is crucial. Mustard algae can lurk unseen, waiting for conditions to become favorable again. Continuous monitoring and maintenance are your best defenses against a resurgence.

Can’t Get Rid Of Mustard Algae? Professional Pool Help Is Just a Call Away

Understanding how to get rid of mustard algae is the first step toward a clear and algae-free pool. However, if you’re in Miami or nearby cities and find yourself in need of assistance, our professional pool cleaning services are here to help. Our team of experts is equipped to tackle even the most stubborn pool problems, ensuring your swimming experience is nothing short of perfect.

Contact us today to reclaim the joy of a crystal-clear pool. With our help, mustard algae will be nothing more than a distant memory, allowing you to dive back into the sparkling waters of your pool with confidence.

Frequently Asked Questions About Mustard Algae On Swimming Pools

What makes mustard algae different from other types of algae?

Mustard algae, characterized by its yellowish-brown color, is more resistant to chlorine and tends to cling to pool walls and the bottom rather than floating freely. It often mimics sand or dirt, making it harder to identify and eradicate than its green counterpart.

Can mustard algae spread to other pools?

Yes, mustard algae can easily spread to other pools through contaminated pool equipment, toys, or swimwear. It’s crucial to thoroughly clean anything that comes into contact with the infected pool to prevent spreading.

How long does it take to completely eliminate mustard algae from my pool?

The time frame can vary depending on the extent of the infestation and the steps taken to combat it. Generally, with diligent brushing, proper chemical treatment, and filtration, significant improvement can be seen within 24 to 72 hours. However, ongoing maintenance and monitoring are key to ensuring the algae does not return.

Why is brushing the pool so important in removing mustard algae?

Brushing helps to dislodge the algae from pool surfaces, making it more susceptible to chlorine and shock treatments. Mustard algae adheres strongly to surfaces, so brushing is a critical step in ensuring that the treatment reaches and effectively kills the algae.

Do I need to drain my pool to get rid of mustard algae?

Draining the pool is not typically necessary and is usually seen as a last resort. Effective brushing, proper chemical treatment, and thorough cleaning of the pool and all related equipment can generally eradicate mustard algae without the need to drain.

How can I prevent mustard algae from returning?

Prevention strategies include maintaining balanced water chemistry, regularly brushing and cleaning the pool, ensuring proper circulation and filtration, and routinely shocking the pool. Additionally, cleaning pool toys, equipment, and swimwear can help prevent reintroduction of the algae.

Should I adjust my pool’s chlorine level if I have mustard algae?

While mustard algae is resistant to normal chlorine levels, increasing the chlorine concentration through shock treatment is an effective method for killing it. It’s important to follow recommended guidelines for shock treatment and adjust your pool’s chlorine level accordingly to effectively combat mustard algae.