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How To Eliminate The Green Water In The Pool

Often, the water in the pool turns green. This phenomenon, caused by the growth of algae, is one of the annoying moments that many pool owners experience sooner or later. Despite this, you can rest assured, as there are preventive methods and effective solutions to get the water in your pool crystal clear again.

Reasons Why the Water in The Pool Can Turn Green

There are different indicators that show algae are growing in our pool. The water changes color and becomes opaque. Then, the walls are slimy and slippery.

The growth of algae is related to four main factors. There may be a problem with the water treatment system, errors in filtration system, improper maintenance of the pool, and perhaps, the water is too hot.

Often, the development of algae is not due to a single cause. Sometimes, it is a combination of factors that promote its growth.

If you detect that algae are growing in your pool, the first thing to do is stop using the pool. It is because the algae growth is often accompanied by an increase of bacteria.

How To Eliminate Algae: Important Steps To Take

You should begin by examining and correcting the pH level. If it is too high (above 7.6, red or purple color in the usual pH analyzers), no treatment will work properly.

If you treat the pool with stabilized chlorine tablets, make sure that the stabilizer level (also known as cyanuric acid) is not too high (above 50 ppm). In that case, the action of the chlorine is blocked and the only solution is to empty a part of the pool (1/4 or 1/3 part as necessary).

Once the pH is verified, you can begin with filtration. Depending on the amount of algae, the filtration time can be quite long. Put the filtration in operation between 24-48 hours, checking during the day if the filter needs to be cleaned (because of accumulation of impurities).

During this process, as soon as you can see the sides and bottom of the pool more clearly, manually brush the areas where there is algae.

What if the Water Still Unclear?

If the water remains cloudy even after this operation, perform a shock treatment.

Add chlorine in the pool to eliminate the algae that are still present in the water (follow the instructions for the dosage). Do not use the pool after chlorine shock treatment. You can use the pool when its value is at the right point.

The waste will be deposited in the bottom of the pool and the water will become clearer. Vacuum dirt using pool vacuum cleaner. To remove impurities from the surface, turn on the filtration system again so that this dirt is sucked up by the skimmers.

If the water is still “dirty” after the shock treatment, you can use a flocculant. It improves the performance of the sand filter and clarifies the water more quickly. During this stage, turn off the pump and do not use the pool for at least six hours. Then, turn on the filtration again and suck the dirt with your vacuum cleaner. Perform a longer “backwash” after this flocculation.


Depending on the spread of the algae, it is possible to complete the treatment by just adding an algaecide in the water. This product destroys the algae with its action.

In summer, the pool is often used more frequently, and the water temperature may be quite high (above 26 ° C). In that case, you will have to increase the daily filtration time so that the water remains clear under all circumstances.

The best way to prevent the growth of algae is to ensure that the conditions of the pool are not favorable for algae growth and development.

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