How to Remove Algae Stains from Pool Walls

If you’re a pool owner, you’re probably all too familiar with the unsightly green or black algae stains that can form on your pool walls. Algae growth is a common problem, especially during the warmer summer months, and it can be a real hassle to get rid of. Not only do these stains detract from the overall appearance of your pool, but they can also be slippery and dangerous if left unchecked.

Fortunately, there are several effective methods for removing algae stains from your pool walls. In this comprehensive guide, we’ll walk you through the step-by-step process of getting your pool walls sparkling clean and algae-free. Whether you’re dealing with a light dusting of algae or a full-blown infestation, we’ve got you covered.

How to Remove Algae Stains from Pool Walls

Algae Growth in Pools

Before we dive into the cleaning process, it’s important to understand what causes algae to grow in pools in the first place. Algae are microscopic, plant-like organisms that thrive in warm, nutrient-rich water environments. They can be introduced into your pool through a variety of sources, including:

  • Airborne spores
  • Contaminated swimsuits or pool toys
  • Inadequate water circulation or filtration
  • Improper chemical balancing (pH, chlorine, etc.)
  • Debris and organic matter in the water

Once algae take hold, they can quickly multiply and spread throughout your pool, causing discolouration and slippery surfaces. Different types of algae can produce different stain colours, from the common green variety to harder-to-remove black or yellow algae.

Preventing Algae Growth

The best way to deal with algae stains is to prevent them from occurring in the first place. By maintaining proper pool chemistry and circulation, you can create an environment that’s inhospitable to algae growth. Here are some key preventative measures to consider:

  1. Ensure Proper Chemical Balance: Keep your pool’s pH, chlorine, and other chemical levels within the recommended ranges. This will help kill off any algae spores before they can take hold.
  2. Run the Filter Regularly: Make sure your pool’s filtration system is operating efficiently and running for the recommended number of hours per day. This will help remove debris and circulate the water to discourage algae growth.
  3. Brush Walls Regularly: Use a pool brush to scrub the walls every week. This will dislodge any algae before it can form stains.
  4. Shock Treat the Pool: Perform a shock chlorination treatment every 1-2 weeks to eliminate any lingering algae or bacteria.
  5. Use an Algaecide: Consider adding an EPA-registered algaecide to your pool’s water regularly to prevent algae from taking hold.

By implementing these preventative measures, you can significantly reduce the likelihood of dealing with stubborn algae stains on your pool walls.

Removing Existing Algae Stains

If you’ve already got algae stains on your pool walls, don’t worry – there are several effective methods for getting rid of them. The approach you choose will depend on the severity of the staining and the type of algae you’re dealing with.

1. Brush and Vacuum the Pool

The first step in removing algae stains is to give your pool a thorough cleaning. Start by using a pool brush to scrub the affected areas vigorously. This will help dislodge any loose algae and prepare the surface for further treatment.

Next, thoroughly vacuum the pool to remove any loosened debris and algae particles. Be sure to clean the filter system as well, as this will help prevent the algae from spreading.

2. Shock Treat the Pool

Once the pool is cleaned, it’s time to shock-treat the water. Shocking involves adding a large dose of chlorine or other oxidizing agent to the pool, which will kill off any remaining algae.

For green algae stains, you’ll want to use a high-strength, fast-acting chlorine shock treatment. Follow the manufacturer’s instructions carefully, and be sure to run the filter for several hours after shocking to circulate the water.

For more stubborn black or yellow algae, you may need to use a specialty algaecide shock treatment. These products are formulated to penetrate and eliminate tough algae growth.

3. Apply an Algae Stain Remover

If the algae stains are still visible after brushing and shocking the pool, it’s time to bring in a dedicated algae stain remover. These products are designed to chemically break down and lift away even the toughest algae stains.

Look for a stain remover that’s specifically formulated for pool walls. Apply it directly to the affected areas, let it sit for the recommended time, and then scrub and rinse thoroughly. You may need to repeat this process a few times for severely stained areas.

When using any pool chemicals or stain removers, be sure to follow the manufacturer’s instructions carefully and take proper safety precautions, such as wearing gloves and eye protection.

Recommended Algae Stain Removers

Here are some top-rated algae stain removers to consider:

Pool Stain Remover by Clorox– Removes tough algae stains
– Safe for all pool surfaces
– Easy to apply and rinse
Algae Stain Remove by In The Swim– Specifically formulated for pool walls
– Works on green, black, and yellow algae
– Non-acidic and non-corrosive formula
Zodiac Pool Stain Remover– Powerful, fast-acting formula
– Removes embedded stains and discoloration
– Safe for all pool surfaces

4. Consider Professional Pool Cleaning

For severe or persistent algae stains, you may need to bring in a professional pool cleaning service. These experts have access to more powerful cleaning equipment and solutions that can effectively remove even the toughest algae buildup.

A professional pool cleaning service will typically start by vacuuming and brushing the pool walls, then use high-powered pressure washing or acid washing techniques to lift away stubborn stains. They may also apply specialized algaecides or oxidizing agents to fully eliminate the algae growth.

While a professional cleaning service may be more expensive than DIY methods, it can be the best way to get your pool walls looking brand new again, especially if you’ve been battling algae for a while.

Preventing Future Algae Stains

Once you’ve successfully removed the algae stains from your pool walls, it’s important to take steps to prevent them from recurring. Here are some additional tips and strategies to keep your pool algae-free:

  1. Maintain Proper Water Chemistry: Regularly test and adjust your pool’s pH, chlorine, and other chemical levels to create an inhospitable environment for algae growth.
  2. Clean the Pool Regularly: Make brushing the walls and vacuuming the pool a weekly routine. This will help dislodge any new algae growth before it has a chance to form stains.
  3. Run the Filter System Efficiently: Ensure your pool’s filtration system is operating at peak performance, running for the recommended number of hours per day.
  4. Use an Algaecide Treatment: Consider adding an EPA-registered algaecide to your pool’s water regularly, as a preventative measure against future algae growth.
  5. Upgrade to a Saltwater System: Converting your pool to a saltwater chlorination system can help reduce the risk of algae by providing a more stable, consistent chlorine level.
  6. Address Any Underlying Issues: If you continue to struggle with recurring algae stains, it may be worth investigating any potential underlying issues, such as poor water circulation, inadequate filtration, or chemical imbalances.

By following these preventative steps, you can help keep your pool walls sparkling clean and free of unsightly algae stains all season long.


Dealing with algae stains on your pool walls can be a frustrating and time-consuming task, but it’s a necessary part of pool maintenance. By understanding the causes of algae growth and implementing a comprehensive cleaning and prevention strategy, you can keep your pool looking its best all summer long.

Remember, the key to effective algae removal is a combination of thorough cleaning, proper chemical balancing, and ongoing preventative measures. With the right approach, you can banish those pesky green, black, or yellow algae stains for good and enjoy a clean, safe, and inviting pool that you can take pride in.

So don’t let algae stains ruin your pool party – follow the steps outlined in this guide, and you’ll be well on your way to a sparkling, algae-free pool that you can enjoy for years to come.

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As the founder of Clean It Spotless, I am Melissa Walker, a leading expert in removing tough stains from fabrics, carpets, and upholstery. With over 10 years of experience in the cleaning industry, I have developed my own natural, non-toxic stain-fighting formulas that lift stains while preserving the integrity of the underlying material. My stain removal tutorials are widely read online, and I have appeared on local TV segments demonstrating my techniques. I also present popular stain removal workshops at community centers and schools.

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