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Algae tend to grow in pools during the warmest months of the year. This is especially true if you have a lot of plant life near your pool, such as trees. If the leaves fall into your swimming pool, they can introduce bacteria and spores into the water.

These spores can turn your water green if the water is imbalanced. If the pH is off balance, the chlorine might not be able to work effectively and kill these spores.

Keep reading if you want to learn how to properly maintain and prevent a green pool fast!

What’s the Best Way to Clean a Green Pool Fast? 

Balancing the free chlorine levels of your swimming pool is the quickest way to clean a green pool fast. Balancing your chlorine doesn’t just mean adding water or chlorine to your pool, but balancing the pool water chemistry overall.

To balance and clean a green pool fast, follow these steps:

  • Scrub your pool liner with a pool brush
  • Skim your pool with a leaf net
  • Use a test kit to determine your pool water alkalinity and pH
  • If your pH and alkalinity levels are balanced, add shock treatment
  • If the pH and alkalinity are too high, you should possibly add acid to your water before adding shock treatment
  • Run pool filter for 6-8 hours
  • Add fresh water to your pool
  • Test your pool chemistry

It’s essential to follow all the instructions in order, or else the pool chemicals might not work correctly. Balancing the acidity of your water before adding chlorine shock to the pool will allow the chemicals to work well and clear your swimming pool water. If the pH levels are too high or too low, it can encourage bacterial growth in the water.

However, if the pH levels are slightly low, you don’t have to add anything to the water. Pool shock will raise the pH of the water automatically, so adding extra may raise it too high.

How Much Chlorine Do You Need to Clear a Green Pool? 

You might be tempted to dump chlorine in your water and hope for the best. However, too much chlorine can interfere with the chemical’s ability to bind to debris and bacteria.

The algae’s color in your pool indicates its strength and intensity. Light green pool water indicates you only have a mild algae growth issue. Adding a moderate amount of chlorine shock will clear your pool.

A single dose of pool shock should clear up a mild growth of algae spores in the water. This is usually approximately 1-2 packages depending on the brand and the size of your pool.

If the algae are dark green or black, your pool has severe growth. You will need to double or triple the recommended shock treatment to clear your pool water. Again, the exact dose varies depending on the size of your pool and the brand. However, a double or triple dose usually equals between 4-6 packets of shock.

What Causes a Green Swimming Pool? 

The two leading causes of a green pool include a dirty filter or an unbalanced chlorine level. Proper pool care includes managing the filtration system and ensuring you don’t have bacterial growth inside it.

Spores can enter your swimming pool through cross-contamination. This can be dirty plant material that falls from trees or other surrounding plant life. Or, it can be brought into the pool by anyone who swims in the water and has a spore on their body.

The spores can turn your water green if the water doesn’t have the appropriate pH balance. The pH levels of your pool are a vital part of pool maintenance since it determines whether spores can grow inside it.

If the water’s acidity is too high, it can interfere with the chlorine’s ability to sanitize the water. If the pH levels are too low, it can create an environment where algae can grow.

What Are the Appropriate pH and Alkalinity Levels?

The best pH levels for your pool are between 7.4-7.6. This is considered a neutral acidic/alkalinity level. If the levels are below 7.4, the pH level is acidic. If the levels are above 7.6, it means the pH level is alkaline.

If the pool’s water is cloudy and grows algae, it could mean the pH level is acidic. This can indicate high amounts of chemicals and bacteria that the filter doesn’t process or clear.

If you’re planning to shock your pool, it’s better to have lower pH levels. This is more effective at killing algae since the shock will also raise your pool’s pH. Running the pool filtration system will ensure the chemicals are evenly distributed throughout the entire pool.

How to Balance Your Pool Water Chlorine Levels? 

Your water’s free chlorine level indicates the amount of contaminants in your water. You can clean your pool faster by ensuring the free chlorine remains between 1-3 parts per million.

The only way to get rid of excess chlorine in your pool is to add water to your pool. This will decrease the amount of chlorine by displacing it.

Reaching the appropriate amount of alkalinity is also essential for balancing your chlorine. Using a chlorine stabilizer such as cyanuric acid in your pool water will prevent chlorine from evaporating because of UV rays.

How to Clean a Dirty Pool Filter? 

One of the main reasons your pool filter isn’t cleaning a pool is that the filter media is dirty. This is typically pool sand, but other types of filtration system media exist. Changing your pool media will ensure the media every 3-5 years will prevent a green pool.

Additionally, check for clogs in the pool pipes. If your pool has a lot of mineral compounds, such as calcium, it can create buildup in your pool filtration system.

Shut off the pool pump and let the water drain. Check each pool tube, flush out any debris you see, and reattach the pool parts. Regular pool maintenance and balancing your pool’s pH is the best way to prevent these clogs in the future.

Why Would Your Pool be Green if Your Chlorine Levels Are High? 

If your chlorine levels are high or balanced, but the water is still green, the cause is likely oxidation. A green pool can be caused by oxidized metals in the water causing the water to look green despite there being no algae spores.

The best way to fix this is to stabilize your pool pH. Add baking soda to the water to lower the acidity of your water, so the water is no longer green.

Can Swimming in a Green Pool be Dangerous?

Swimming in a green pool is dangerous because it probably has a lot of bacteria growing in it. Most of the time, a green pool has a lot of hazardous bacteria, such as E. Coli. This bacteria can cause dehydration and severe digestive issues.

Most of the time, a green pool will just irritate the skin and eyes, though. This is especially true if your pool has a high chemical and mineral imbalance. You should also avoid swimming in a pool that was just treated.

Chorine and shock have high acidity and can be corrosive to your skin and eyes. Avoid swimming in green pools for your own safety.


Algae grow in pools that have a chemical imbalance. It’s especially likely to increase in pools where the water is hot, and unless you remove all the algae, it can respawn when the opportunity arises.

Try to ensure you remove dead algae after treating your pool. This will help guarantee that the pool algae doesn’t grow back!

Scrub your pool thoroughly before treating it to make sure you loosen any algae clinging to the walls or floor. If you have a concrete pool, you’ll want to use a tough bristle brush to remove it from the crevices.


How Do You Know When Your Pool is Safe to Swim in? 

Test the pool’s free chlorine before swimming in it again. Not only do you want to water to be clean, but you want your pool to have a balanced chemical level. If chlorine is high in your pool, it can hurt your skin and eyes.

Can You Bring Algae Spores to Your Pool Water on Your Bathing Suit?

Yes, you can bring algae spores into your pool on a bathing suit or swim shoes. Make sure you kill algae on contaminated clothes before jumping into the pool. You can bleach or wash them thoroughly before entering your swimming pool.

If you recently swam in a lake or the ocean, there’s a good chance your swim gear’s contaminant. To prevent a green pool, wash all your clothes thoroughly as soon as possible!

What is Calcium Hypochlorite? 

Calcium hypochlorite is another name for chlorine. However, it’s more specifically sodium by-product used to create bleach and other cleaners.

Is Green Water Different From Cloudy Water?

Yes, green water is different from cloudy water. If you have cloudy water, it can indicate algae spores, bacteria, and other contaminants. But it can also mean the chemical and mineral levels are too high, and you need to balance the pool.

Cloudy pools can be balanced by cleaning your pool with a pool vacuum and skimmer. Although, you may need to add fresh water to your pool as well to displace the chemicals and minerals.

How Often Should You Clean Your Pool to Prevent Algae Growth?

You should check your pool’s chemical balance every day. A day of imbalanced pH can create a breeding ground for bacteria and algae.

You should clean your pool with a pool brush and skimmer every week. This will remove algae and organic debris that accumulates in the water. Eliminating these contaminants will help prevent your pool from becoming green.

Where Does Algae Grow?

Algae grow in warm water environments where the alkalinity is favorable. It’s most likely to start to develop in the corners and crevices of your pool walls and filter.

Regularly washing the pool algae off the walls and balancing the water chemistry will prevent this!