My pool water is green, what should I do?

Regular maintenance of your pool is essential to maintain clear and clean water. However, despite your efforts, it may happen that your pool water turns green .

Typically, this phenomenon is caused by algae blooms , which are encouraged by conditions such as high temperatures, chemical imbalance in the water, or insufficient filtration. Fortunately, there are effective solutions to quickly restore healthy water and restore your pool to its former glory.

Find out the steps to follow to effectively treat a swimming pool with green water .

Why is my pool water green?

When your pool water turns green , it indicates the presence of algae. Several factors can promote this proliferation:

– Insufficient disinfectant level: Disinfectants such as chlorine and bromine are essential for maintaining a clean and healthy pool . And for good reason, they destroy bacteria, viruses and algae present in the water. If the chlorine or bromine level is too low, algae can grow freely.

– Imbalanced pH : The pH of water, which measures its acidity or alkalinity, is crucial to the effectiveness of disinfectants. A pH above 7.5 can make disinfectants less effective and promote algae growth .

– Ineffective filtration: A high-performance filtration system is essential to maintain the cleanliness of pool water . Filters remove impurities and suspended particles, including algae. If the filter is clogged or poorly maintained, algae can proliferate.

– High temperatures: Heat is a key factor in the development of algae . High temperatures, responsible for increasing water temperatures, accelerate the growth of algae .

– Stagnant water: Poor water circulation can create stagnant areas where algae can thrive undisturbed.

– Organic debris: Leaves, twigs and other organic matter falling into the pool provide nutrients to the algae, promoting their growth.

– Exposure to sunlight: Finally, sunlight promotes photosynthesis in algae, allowing them to grow more quickly.

By understanding these factors and taking appropriate measures, you can effectively prevent and treat algae growth in your pool .

Swimming pool: the water is green, what to do?

Summer is fast approaching and you discover that the water in your pool has turned green . Don't panic! There are several solutions to get your water clean and healthy quickly.

1. Analyze the pool water

Start by testing your water parameters using test strips or an electronic tester. Here are the essential things to check if you want to restore water balance :

– Adjust the TAC (Total Alkalimetric Title) : The TAC should be between 80 and 120 ppm (parts per million). If the TAC is unbalanced, add the corrective product all at once in a corner of the pool with the filtration stopped. Then restart the filtration for 24 hours to mix the product well in the water.

– Adjust the pH level : The pH of the water must be adjusted to between 7 and 7.4. To do this, use pH Minus or pH Plus (depending on the result obtained). Dilute the product in a watering can and pour it slowly in front of a discharge with the filtration running. Repeat the operation in increments of 0.2 until the desired pH is reached.

– Check the TH (Hydrotimetric Title) : The TH, which measures the hardness of the water, must be between 100 and 200 ppm. If the TH is too high (above 300 ppm), use a limestone sequestrant to prevent limescale deposits and protect your equipment.

2. Perform shock treatment 

The second step is to perform a shock treatment using the appropriate disinfectant, such as chlorine shock or bromine shock . If your pool is treated with chlorine, you will need to use a chlorine shock treatment.

Here are the steps to follow to ensure the effectiveness of the treatment:

– Preparation of the treatment: Measure the quantity of shock chlorine or shock bromine recommended for your pool. This dosage depends on the volume of water in your pool and the concentration of the product.

– Applying the treatment: Spread the shock treatment product evenly over the entire surface of the pool water . It is often advisable to dilute the product in a bucket of water before pouring it to avoid too high a concentration in one place.

– Filtration activation: Put your filtration system into forced operation and let it run continuously for 48 to 72 hours. This step is crucial because it allows the water to circulate continuously, thus ensuring that the treatment is well distributed throughout the pool.

– Monitoring and adjustments: During this period, regularly monitor the condition of the water and the operation of the filtration . If necessary, clean the filter to prevent it from becoming clogged with algae residue .

Please note that the filtration must operate continuously throughout the shock treatment . If the filtration system stops, even temporarily, this may compromise the effectiveness of the treatment and you may have to start the process again.

3. Thoroughly clean the pool

To permanently eliminate algae and fully enjoy your pool, you will then need to thoroughly clean the pool. Start by vigorously brushing the walls and bottom of the pool to loosen and remove dead algae. Use a brush suitable for your pool's coating so as not to damage it.

Also clean the filter and skimmer basket to ensure optimal water circulation. For pools equipped with a sand filter , backwash and rinse the filter to remove accumulated impurities. This will allow your filtration system to operate efficiently and prevent further algae proliferation.

Add algaecide

Is your pool properly cleaned? It's time to move on to anti-algae treatment to prevent any new growth. Algaecide is a chemical product designed to kill and prevent the proliferation of algae. In general, it is recommended to add 1 liter of algaecide per 100 m³ of water.

For effective application:

– Dilution and distribution: Dilute the algaecide in a bucket of water, then pour it evenly around the pool, near the return jets if possible, to ensure even distribution.

– Action time: Let the anti-algae product act for 6 to 12 hours. Make sure your filtration system runs continuously for 24 to 48 hours. 

For personalized advice, do not hesitate to consult pool maintenance experts.

Use flocculant

To clarify swimming pool water that has turned green , using flocculant is an essential step. Flocculant is a chemical that helps to agglomerate fine particles suspended in the water, responsible for turbidity and the cloudy appearance of the water .

Once the solution has been poured into your pool water, let the filtration run for 24 hours before finishing by washing and rinsing the sand filter .

Do you have a cartridge filtration system ? Be careful, flocculation can damage it. Make sure you get special flocculants that will not damage your equipment.

Now you can enjoy your swimming pool! 

How to stop pool water from turning green?

As the saying goes, “ prevention is better than cure .” To prevent your pool water from turning green during the swimming season, just follow these steps:

Perform regular testing

Monitor pH and disinfectant levels frequently to maintain optimal water balance. Regular monitoring ensures disinfectants remain effective and water remains clean and safe.

Clean the filter

Ensure your filtration system is working efficiently by cleaning your filter regularly. This prevents the build-up of debris and impurities that could promote algae growth , contributing to clear, clean water.

Use a tarp

Protect your pool by using a cover to prevent debris from falling into the water and reduce exposure to sunlight. This helps limit algae growth by blocking some of the sunlight needed for algae to grow.

Add anti-algae to your daily treatment

Incorporate a few drops of algaecide into your daily water treatment routine to prevent algae growth. This proactive measure will keep your pool water clear and algae-free at all times.

By following these steps, you can prevent your pool water from turning green and enjoy crystal clear water throughout the swimming season. If problems persist, do not hesitate to contact the experts at Aboral Piscines for additional, personalized advice.