Easy Steps for Restoring a Green Pool to Its Former Self

The same way you got a green pool, you can also clean your pool and get it back to its former glory. Here are the steps you need to follow to get started!

Have you got a green pool? It’s time to fix the problem.

You’re not alone in feeling frustrated when your pool turns green. Green pool water is caused by excess algae that can be difficult to remove. However, once you know what type of green water you have and its underlying cause, it’s a lot easier to get rid of it for good. 

As a rule of thumb, the deeper the shade of green in your pool, the more algae have grown. Algae are usually green because they take in too much light and nutrients from your pool.

Green Pool: Algae

When these conditions are present, algae grow fast enough to outpace the rate of photosynthesis and stay in the water for long periods. They also cause a lot of problems in your pool.

There are various methods for treating your pool with chlorine, some of which may be completed by the homeowner, while others are better left to the expertise of a pool professional.

This article will explore what causes of green pools and how to fix them.

Why Do Algae Infiltrate Pools?

Algae infest pools for a variety of reasons. The conditions that lead to the infestation are usually due to chlorinated pool water, which is an environment algae thrive.

Other potential causes are stagnant and high levels of organic material, low levels of oxygen in the water, large amounts of light, excessive nutrients, and algae-friendly pH levels.

When these conditions present themselves, they’re often accompanied by other signs like cloudy water or brown scum on the sides and surfaces of the pool. Different types of green algae also proliferate in pools with poor hygiene and maintenance. 

Green Pool: Algae swimming Pool Filter

What Are the Other Causes of a Green Pool?

Let’s look at some of the other possible reasons for green water in your pool before we discuss how to shock your pool to remove ugly algae blooms.

Since this issue is not always caused by insufficient chlorine levels enabling algae to develop, it is important to understand what may generate the foul, sickly color in the first place.

  • Green pool water is sometimes caused by a faulty pump or filter. Also, if your pump and filter size is too small, it isn’t enough to prevent algae from growing. Furthermore, if your pool has the right size of pump and filter, but you don’t run it for eight hours every night, it may not remove algae spores effectively.
  • Filtration issues also cause a green pool. If your pool includes a sand filter, cleaning it may take a week or more. If your pool has a cartridge filter, you may need to clean it daily until the water is clear and goes back to normal.
  • Your pool water may also turn green because of exposure to oxidized copper. However, this may not be the issue because it’s a rare occurrence for pool owners. Often, when copper comes in contact with your pool via corrosion or copper heaters, your pool water may turn green. If you believe this is the source of your problem, it’s best to leave it to the hands of the pool expert to fix it for you. 

Guided Easy Steps for Clearing Out Green Pool Water

Most pool owners have to deal with green water at least once every year. While it’s usually just temporary, sometimes it becomes permanent. Here are some steps you can follow to clear out your green pool water effectively.

These simple steps should get rid of green algae growth within a few couple of days.

1. Start Vacuuming Your Pool to Waste

Vacuuming your pool to waste is one of the most effective ways to remove green algae because it’s an efficient way of redistributing water.

Set your filter’s valve to waste and vacuum away, eliminating as much algae as you can.

Green Pool: Vacuuming your pool to waste

2. Clean the Pool Walls and Floor With a Stiff Bristle Algae Brush

To effectively clean algae from your pool, it is preferable to use an algae brush rather than your normal pool brush.

Green Pool: Stiff Bristle Algae Brush

This heavy-duty brush works better than soft nylon bristles for removing algae from pool surfaces since algae are strong and will persistently stick to the pool walls and surfaces.

Green algae must be removed from your pool’s walls and the floor immediately since they can alter the balance in your water.

3. Clean or Change the Filters

If you’ve been going through problems with your pool for several months now, changing filters regularly could be beneficial. Changing them often helps prevent the buildup of debris and algae spores inside the filter system.

Green Pool: Clean Filter

4. Keep Your Pool Free From Saltwater

If you live near saltwater beaches, then there’s a good chance that your pool has accumulated salt over the years. This causes your pool to become more acidic, making it a good environment for algae to thrive. 

5. Check for Leaks

Leakage is also a common cause of green pool water. If you suspect that this may be the case, check your pool pump seals and replace them if necessary. Also, look into replacing your skimmer basket if possible.

6. Check the pH and Alkalinity Levels of Your Pool

It’s also recommended to check your pool’s pH and alkalinity level, which will reveal the water’s pH needs. If it is not within the desired range, you can then balance the chemical by adjusting the water with a commercial product or using a home remedy.

Green Pool: Check the pH and Alkalinity Levels of Your Pool

Remember: You must adjust your pool’s pH levels because algae will be more likely to grow if they are too high.

7. Chlorine Shock Your Green Pool to Eradicate Algae

It’s time to shock your green pool with chlorine really hard to eradicate the algae. Chlorine is a disinfectant, and algae cannot stand exposure to it for a prolonged time.

To get the greatest results, use a shock solution that contains at least 70% chlorine and shock the green pool two times.

Green Pool: Chlorine Shock Pool

8. Keep the Filter Running!

The filter is a vital component in killing green algae. It does not eliminate the algae independently, but it helps disperse and spread it over a larger area. 

Keep the filter running after you’ve shocked the green pool the number of times you want to shock it and don’t turn the filter off until the water is spotless. Your water will usually clear out in five days or less. 

9. Test, Balance, and Enjoy!

When your pool no longer looks green, it’s time to test the water again, not just pH and alkalinity but also sanitizer levels. 

Make sure to bring your pool’s chemistry back to equilibrium by adding chemicals. 

Check everything one last time. Then if everything seems working properly, it’s time to enjoy your pool once again.

Frequently Asked Questions (FAQs)

Can I swim in a green pool?

Swimming in a green pool is not recommended due to potential health risks associated with algae and imbalanced water chemistry.

How long does it take to clear a green pool?

The time it takes to clear a green pool depends on the severity of the algae infestation and the effectiveness of your treatment. It can take several days to a week or more.

What are the health risks of swimming in a green pool?

Swimming in a green pool can lead to skin and eye irritation, as well as potential health risks from exposure to algae and bacteria.

How often should I test my pool water for chemistry levels?

Regularly test your pool water at least once a week, especially during the swimming season, to ensure proper chemistry levels.

Can I use natural or eco-friendly methods to treat a green pool?

While some eco-friendly pool treatment methods exist, addressing severe algae problems often requires chemicals to ensure effective treatment.


Now that your pool is back to its original blue color, and you can see the floor once again, pat yourself on the back for completing a job well done. But unfortunately, pool algae pose a threat to swimmers’ safety. So, let’s make sure it doesn’t come back. And if it comes back, you’ll be prepared for whatever happens. Enjoy.

Learn more about maintaining a clean swimming pool and keeping it safe for your family. You can find more pool-related articles on our website.

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About the author

Brian Anderson

The rather dry pool world out there is in need of some passion to make it shine. With the help of my son Ruben and his wife Maria our mission is to help you create the favorite spot of your house - your pool.

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