How To Get Rid Of Green Algae: An In-Depth Pool Care Guide

Finding green algae in your pool may raise questions. While most types of algae are not harmful themselves, they can create an unhealthy swimming environment. This guide provides all the information you need to tackle green algae - where it comes from, how to spot it, how to kick it out, and even how to keep it away. So you can enjoy a safe and squeaky-clean pool!

How To Clear A Green Pool

The process of reviving a green pool to its crystal-clear, appealing state is a methodical one. By following these detailed steps, you can efficiently eliminate the green menace from your pool.

  1. Test Your Pool's Water Chemistry

The first step towards a clear pool is understanding the chemical composition of your pool water. Testing pH and alkalinity levels provides crucial insights into your pool's health. The ideal pH level, the measure of acidity or basicity, should lie between 7.2 and 7.6. An imbalance can render chlorine less effective and promote algae growth. Alkalinity, acting as a pH buffer, should be maintained between 80 and 120 parts per million. Test kits are readily available and easy to use, providing you with immediate results to make necessary adjustments.

  1. Shock Your Pool

'Shocking' your pool refers to the process of adding a high dose of chlorine to kill algae. This shock treatment temporarily elevates chlorine levels to break down organic contaminants and restore water clarity. It's crucial to follow the manufacturer's instructions on how much shock to use based on your pool size. Aim to do this at dusk or night to prevent the sun from burning off the chlorine too quickly and remember to run your pool filter during this process.

  1. Algaecide Treatment

After the shock treatment, an algaecide application helps tackle any remaining algae. Algaecides are formulated to target the algae cell structure, effectively killing it off. This treatment not only eliminates persistent algae but also creates a hostile environment for future growth. Make sure to follow the algaecide instructions to determine the correct amount for your pool size.

  1. Brush and Vacuum

Post-chemical treatment, manually cleaning your pool is necessary to remove dead algae and debris. Brushing your pool walls and floor dislodges any clinging algae, which can then be vacuumed up. Manual vacuuming is often more effective than automatic pool cleaners for a thorough clean-up after an algae bloom.

  1. Filter

The final step is running your pool filter continuously for at least 24 hours to remove the dead algae and any leftover debris. This process also helps distribute pool chemicals evenly, aiding in overall pool sanitation. After the filtration process, remember to backwash or clean your filter to maintain its efficiency.

As you can see, tackling green algae on your own can be time-consuming and tricky. Hiring a professional green algae removal service ensures a swift and effective solution. Experts possess the knowledge and experience to eliminate algae effectively and prevent future outbreaks. Now that you know how to clear green algae, let's explore what causes it so you can prevent it from coming back.

What Causes Swimming Pool Algae? 

Swimming pool algae is the result of a combination of factors. The three main culprits are inadequate water circulation, poor sanitation, and an imbalance in water chemistry. Algae spores can be brought into your pool through wind, rain, or contaminated equipment. Once inside, they thrive in warm, sunny environments and multiply quickly in stagnant water or on pool surfaces that aren't brushed regularly.

What Are The Different Types of Pool Algae?

To clear your pool of algae effectively, you need to identify the type of algae that is present. Green algae (Chlorophyta) is a common one found in pools and spas. It's slimy and loves still water. Treating green algae promptly is essential to prevent it from spreading and causing more problems.

Some other types of algae that might feature in your pool include:

  • Yellow: This species, also known as mustard algae, characteristically exhibits a muddy color with yellow undertones. Due to its resistance to normal levels of chlorine, mustard algae is harder to remove compared to other species.
  • Black: Primarily found in lakes and ponds, black algae are more severe as they can penetrate harder surfaces like concrete. They have strong roots and often regrow after being removed. It's crucial to rigorously clean and treat the affected area to completely eliminate them.
  • Pink: This kind of algae, observed at the water line in your pool, is caused by a specific type of bacteria but is generally easy to remove. Ignoring them, however, can cause stains which are unpleasant to look at and hard to remove.
  • Blue-Green: Typically classified as black algae, blue-green algae requires immediate treatment to prevent penetration into hard pool surfaces. Unattended blue-green algae can quickly turn a pool into a murky, cloudy mess that's unfit for swimming.

Each type of algae requires a slightly different treatment method, but prevention is universal. Proper pool maintenance, including regular brushing and maintaining the correct water chemistry, can prevent any type of algae from setting up home in your pool.

How To Preventing Algae Growth in Your Pool

Algae prevention is less labor-intensive and more cost-effective than removal. By keeping the following preventative measures in mind, you can keep your pool sparkling all year round.

Regularly Test and Adjust Your Pool Water Chemistry: Regular testing of your pool water's pH and alkalinity levels can help you maintain the right balance. An imbalance can render pool sanitizers ineffective and provide a conducive environment for algae growth.

Proper Maintenance of Your Pool Filtration System: Your pool filter is a primary defense against contaminants, including algae spores. Regular backwashing or cleaning, depending on your filter type, ensures it functions efficiently.

Routine Brushing and Vacuuming: Regular brushing prevents algae from adhering to pool surfaces, and vacuuming removes any potential algae spores. Areas with low water circulation, such as behind ladders, pool steps, and corners, should be given special attention.

Use Algaecide As Part Of Your Routine Pool Maintenance: Regular use of algaecide can ward off potential algae blooms. Adding it after every shock treatment can prove beneficial in keeping your pool algae-free.

By incorporating these steps into your regular pool care routine, you can enjoy an algae-free, inviting swimming pool.

How To Remove Algae Stains from Pool Walls

If your pool walls are stained with algae, you may need to drain the water and clean the pool thoroughly. Algae stains are not just unsightly but can also lead to long-term damage to your pool surfaces if not addressed promptly. The use of Muriatic Acid can help effectively eliminate these stains. However, exercise caution when handling this substance. Protections, like strong gloves, should be worn for safety while using this acid. Additionally, avoid contact with the skin or eyes and ensure that the area is well-ventilated during usage.

Is Algae In A Pool Dangerous? 

While most types of algae are not harmful themselves, they can create an unhealthy swimming environment. Algae in the pool can lead to cloudy water and reduced visibility, posing a safety risk. It can also create a slippery layer on pool surfaces, increasing the risk of slips and falls. Moreover, algae can clog filters, leading to poor water circulation and potentially costly repairs.


Tackling green algae in your pool requires specific strategies and regular maintenance. For help with your pool care, consider Flow Pool Care in Austin, TX. Their knowledgeable team will help you identify the root cause of algae growth and implement effective strategies to prevent future outbreaks.

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