With the warmer weather, many people open up their pools for the season. However, one common issue that pool owners face is algae. Algae can quickly take over a pool, making it unsafe to swim in and causing the water to turn an unsightly green.

This article will discuss how to kill and prevent algae growth in your pool so you can enjoy a clean and refreshing swim all season long. Let’s get started.

Types of Pool Algae

Three main types of algae can grow in pools:

  1. Green pool algae, also known as “Mustard Algae,” is a type of algae that has a green tint and often grows in patches. Green algae are commonly found in poorly sanitized pools and typically form on the walls or floor of the pool.
  2. Yellow pool algae, also known as “Golden Algae,” is a type of algae that has a yellow tint and often grows in clumps. This type of pool algae is commonly found in pools that are not properly circulated and typically form on the surface of the water.
  3. Black pool algae, also known as “Black Beard Algae,” is a type of algae with a black tint and often grows in mats. This type of pool algae is commonly found in pools that are not properly balanced and typically form on the walls or floor of the pool.

How to Kill Algae in Pool?

Some pool owners may overlook the algae in their pool, thinking it’s not a big deal. After all, it’s just a little green growth, right? But many people don’t realize that algae can harm your pool and health. Algae can cause your pool to become murky and dirty, and if you or your family swim in a pool with algae, you could end up with rashes or other skin irritations.

So how do you get rid of pool algae in your pool? There are a few different methods you can try, including:

1. Vacuum Your Pool Manually

The first step in removing algae is to vacuum it up manually. Use a pool brush to scrub the walls and floor of your pool, paying special attention to any areas where algae are present. Be sure to vacuum the entire pool, not just the areas where algae are visible. To kill algae in your pool, you must vacuum it manually on the filter’s waste setting. This will allow you to bypass the filter and prevent any contaminated, algae-filled water from recirculating back into the pool.

2. Brush Your Pool Walls and Floor

When you vacuum up algae, you only get rid of the surface-level stuff. To get rid of all the algae, you must brush the walls and floor of your pool. Use a stiff-bristled brush to scrub away any remaining algae. Be sure to brush all pool areas, including corners and stairs.

Scrubbing the algae supports chlorine getting deeper into the remaining algae, killing it more effectively. As you go, your water will become cloudy, obstructing your view, so brush the tougher spots first. If you have a concrete or gunite pool, use a pool brush with stainless steel bristles to remove algae from your pool walls. Be sure to brush all pool areas, including corners and stairs.

3. Test and Balance the Water

One of the reasons algae thrive in pools is because of imbalanced water. Test your pool’s pH levels and adjust as needed. You should also test your pool’s chlorine and alkalinity levels and ensure they are within the proper range. To kill algae in your pool, you must first test the alkalinity and pH levels. This will ensure that your sanitizer will be effective. Then, it would help if you shocked the pool. Finally, it would help if you filtered out the algae.

4. Shock Your Swimming Pool

Shocking your pool is a great way to kill algae and prevent it from returning. Be sure to follow the manufacturer’s instructions when shocking your pool. Adding shock to your pool will increase the amount of chlorine in the water and kill algae growth. It is best to shock your pool at dusk or night so that the sun does not consume most of the chlorine.

Also, put your cleaning equipment in the shallow end of the pool so it can get sanitized by the shock. Run your filter for eight hours or overnight to circulate the shock throughout the pool. If there is still a lot of algae, repeat the brushing process and shock.

5. Filter Out the Pool Algae

When you shock your pool to kill the algae, the water will turn a cloudy blue. This is normal and means that the algae are dead. The Gray, dead algae particles must be filtered out of the water.

Once you’ve shocked your pool, it’s time to filter out the algae. Run your pool filter for 24 hours to remove any remaining algae from the water.

6. Test Your Pool Water Again

After you’ve filtered the algae out of your pool, test the water again to ensure the levels are balanced. Adjust the pH, chlorine, and alkalinity levels as needed. It is important to ensure that your pool’s water chemistry is balanced and the chlorine levels are back to normal before anyone uses the pool again. You may need to adjust the alkalinity, pH, and chlorine levels. It is also a good idea to test the cyanuric acid and calcium hardness levels since you have replaced some pool water with fresh water.

7. Clean Your Pool Filter

It’s important to clean your pool filter regularly to prevent algae from growing back. Be sure to follow the manufacturer’s instructions when cleaning your filter. If you want to prevent algae from growing in your pool, it’s important to clean your filter regularly. Cartridges can be soaked in diluted muriatic acid or replaced entirely. If you have a sand or D.E. filter, remember to backwash periodically. Keeping your filter clean will create a less hospitable environment for algae growth.

How To Prevent Algae In Pool?

You can take some preventative steps to help keep algae from taking over your pool in the first place. They include:

1. Test The Water’s Alkalinity and pH Levels.

The ideal pH level for pool water is 7.4. Alkalinity should be between 80 and 120 ppm (parts per million). If the alkalinity is too low, it can cause the pH to fluctuate. This creates an environment that’s ripe for algae growth.

To test your pool water, use a reliable test kit. You can purchase one at a local pool supply store or online. Test the water according to the manufacturer’s instructions and adjust as needed.

2. Running Filter

Your pool filter is key to keeping the water clean and clear. It removes dirt, debris, and microorganisms from the water. Make sure to run your filter according to the manufacturer’s specifications. This means running the filter for 8 to 12 hours per day for most pools.

3. Vacuuming

Regular vacuuming helps remove the pool’s dirt, debris, and other organic matter. This is important because organic matter can contribute to algae growth. Be sure to vacuum your pool at least once a week.

4. Shock Your Pool

Shocking your pool involves adding a concentrated dose of chlorine to the water. This kills bacteria and other microorganisms that can cause algae growth. Shocking also helps remove any build-up of chloramines, which can occur when chlorine mixes with sweat, skin oils, and other debris.

To shock your pool, follow the manufacturer’s instructions for adding the chlorine. Be sure to run the filter for 24 hours after shocking the pool.

5. Add An Algaecide

An algaecide helps prevent algae growth by killing algae and bacteria. It’s important to add an algaecide to your pool regularly, especially during the summer months. Follow the manufacturer’s instructions for adding the algaecide to your pool.

6. Regular Maintenance Schedule For Pool Cleaning

To keep your pool clean and clear, it’s important to develop a regular maintenance schedule. This should include testing the water, running the filter, vacuuming, and shocking the pool regularly. Be sure to add an algaecide to your pool monthly. Following these steps can help prevent algae growth and keep your pool looking its best.


Is It OK To Swim In Pool With Algae?

No, it’s not advisable to swim in a pool with algae. Algae can cause skin irritation and other health problems. You should clear them from pool surfaces and treat algae problems.

What Causes Algae In A Swimming Pool?

Many factors can contribute to algae growth in pools, including warm temperatures, sunlight, high pH levels, and lack of circulation.

Should I Use Shock Or Algaecide First?

It’s generally recommended to use shock treatment first, as this will kill any algae in the pool. Algaecide can then be used as a preventative measure.

Can Too Much Chlorine Cause Algae?

While chlorine is essential for keeping pools clean, too much can promote algae growth. It’s important to maintain proper chlorine levels to prevent algae growth.

What Causes Algae Blooms?

Algae blooms occur when there is an excess of nutrients (nitrogen and phosphorus) in the water. These nutrients come from many sources, including agricultural runoff, sewage effluent, and urban stormwater runoff.

Algae blooms can have several negative impacts on the environment and human health. They can lead to the depletion of oxygen in the water. Also, they can make the water unsafe for swimming and other recreational activities.

How Can I Prevent Algae Blooms?

You can help prevent algae blooms by reducing the number of nutrients that enter the water. This can be done by properly disposing pet waste, fertilizers, and other household chemicals. You can also help by volunteering for or participating in local watershed cleanup efforts.

How Do I Get Rid Of Algae?

If you find algae in your pool, remove it as soon as possible. Several products are available that will kill algae and prevent it from returning. Be sure to follow the manufacturer’s instructions carefully to avoid harming yourself or the environment.

What Kills Algae In A Pool Fast?

Algae can be killed quickly with the right pool chemicals and products. Chlorine is the most common and effective way to kill algae, but other options include bromine, algaecides, and mineral sanitizers. Shock treatments are also sometimes used to achieve fast results.

What Dissolves Algae In Pool?

There are a few different ways to dissolve algae in your pool. One is to use a chemical cleaner to break down the algae cells. You can also use a pressure washer or brush the algae off surfaces. Finally, you can vacuum the algae out of the pool.


Algae can be a nuisance in your pool, and it’s important to take care of it as soon as possible. They can make your pool look dirty and can be dangerous for swimmers.

There are several ways to kill algae in your pool, including chlorine, bromine, or other chemicals. You can also try using a pool brush to scrub the algae off your pool’s walls and floor.

To prevent algae from growing in your pool in the first place, you should test your water regularly and adjust the pH levels as needed. You should also keep your pool clean by vacuuming it regularly. Following these tips, you can enjoy a clean and safe pool all season long!

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Last Updated: November 20, 2022 / Categories: Outdoor & Garden, Pool & Spa / 9.4 min read / Tags: , /

About the Author: Kara Toomey

Kara Toomey

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