It will not surprise you to learn that pool water turns green when algae invade it. These
can develop rapidly overnight in summer. What are the main
reasons? An unbalanced water and a lack of chlorine. Has the water in your pool turned green? Do
n’t worry, today we explain how to Pool cleaner, so that your pool is
clear and crystal clear like the first day.
Why is my pool water green?
There are numerous causes that can cause green water in your pool. Although the most common
is the proliferation of green algae, spring pollen or the presence of copper in the water as well.
They may be at the source of the problem.
- Algae: green and cloudy water
When the transparent and clear water of your pool turns green and cloudy, we are facing an
invasion of pool algae! The pH of your water is surely too high, thus limiting the effect of your disinfectant.
- Copper: clean water and light green
Poor quality algaecide, a piece of metal that has fallen to the bottom of the pool, acidic fill water or a very low pH rate can be the cause of the presence of copper in the pool.
In spring, pollen can cause slightly greenish water. If you don’t have allergies, you don’t have to worry. Just connect the water filter for several hours and the problem will be solved
- The sand in your filter hasn’t been changed in several years
If your pool has a sand filter, it is advisable to change the sand every 3 to 5 years. If you have never done it before, it is possible that the water in your pool turns green due to poor filtering.
- A pool with a protective shutter and with a lot of heat favors the proliferation of algae.
Protective shutters have many advantages: they protect the water in your pool against impurities, they maintain the temperature if the pool is heated… But on hot summer days, they can
cause a large increase in water temperature, which can cause the proliferation of algae and consequently a green water.
- The water heating is too high.
For the same reasons as the previous point, the higher the water temperature, the greater the risk of it turning green. Chlorine is less effective when the water temperature exceeds 24°. Heating your pool water to a high temperature has a direct influence on the color and quality of the water.
- A lot of influx in your pool.
The more bathers there are in your pool, the risks of it turning green increase. During the summer season, and after an afternoon bathing with family or friends, disinfectant products are consumed faster. In these cases, it is advisable to analyze the water often and check that it is balanced.
- Presence of fertilizers in the pool.
Is your pool in the middle of the garden and have you recently planted grass or flowers? A simple draft of air can cause the fertilizers to reach the water. Most of the time, these types of fertilizers are rich in nitrates and phosphates, which accelerate the development of algae.
How to fix the problem?
What product to use for green water?
To know the origin of green water, get a complete water analysis kit. This should include:
- A test for copper
- A test for pH
- an alkalinity test
- A test for calcium
If your pool is green due to the presence of green algae in the water, you will have to buy a chlorine-based disinfectant product (with an active chlorine rate of over 70% to apply a shock treatment to the pool water).
Clean the green water in your pool step by step:
- Clean your pool with the robot vacuum cleaner. The first step to combat the problem is to pass the robot to remove all the impurities present at the bottom of the pool. Remove as much of the residue or sediment present on the bottom to complete this first step.
- Brush the walls of the pool. In this step, equip yourself with an algae brush with hard bristles instead of a soft nylon brush. Green algae stick to walls a lot. Once equipped, roll up your sleeves and build muscle by thoroughly rubbing the walls and bottom of the pool.
- Check the pH and alkalinity of your water. Now that you have cleaned the pool with the robot and brush, you will need to analyze the water balance with an analysis kit. This stage is important, since the results of this first test will serve as a reference for a second analysis, when the water is clear and clean again.
- Balance the water. The effectiveness of chlorine depends on the balance of the water, therefore, before adding the product, regulate the TAC of your pool and then its ph.
- Carry out a chlorine shock treatment. This stage is the most important to get rid of algae in your pool and get clear water. The shock treatment will suddenly raise the percentage of chlorine in your water and permanently eliminate the algae. We advise you to carry out this shock treatment step at least twice, and if the color of the water is dark green (high concentration of algae) do not hesitate to repeat it 3 or even 4 times.
- Turn on the filter, and let it work. We’re almost done! Now that we have taken care of the pool and applied the corresponding treatment, we have eliminated the algae. Now you just have to remove them from the water by turning on the filter to see your pool again clear and crystal clear. Do not forget to be patient, since after a treatment of this style, you will need 4 to 5 days of intensive filtering.
You can use a clarifying agent to speed up the process. If you decide to use it, you will still have to leave the filter active for a minimum of 24 hours.
- Check your water balance again. Now that the green water has disappeared and your pool looks clear and clean like the first day, don’t forget to do a new water test.
Now that your pool water is clear again, you should run an analysis to check the pH, alkalinity and chlorine level. If it’s still out of balance (remember: pH at 7, alkalinity around 100 ppm) correct it.
Discover how to perform a shock treatment with chlorine in 6 stages!
Important: Even if you do not usually use chlorine in your pool (salt pool, bromine or others), it is necessary to use chlorine to recover a pool with green water, and more importantly, choose the appropriate chlorine treatment! Once you have carried out the treatment, you can go back to using the disinfection method that you used previously.
Finally, if you have followed our process, you should be able to bathe in your pool again with clear water since, although water highly laden with chlorine is aggressive for the skin, eyes and mucous membranes, evaporation and filtration quickly eliminate the excess chlorine. In other words, you can bathe without any problem 24 hours after having carried out the shock treatment with chlorine.
What to do to conserve crystal clear water?
You can very easily avoid the problems caused by green pool water by regularly checking the following points:
- Regularly check the stability of the pool water
To prevent water from turning green, always maintain an ideal pH between 7.2 and 7.4.
As important as the pH is also the measurement of the TAC of your pool (Complete Alkali metric Title). This index measures the alkalinity of the water, that is, the concentration of minerals. A good balance allows, among other things, to limit variations in the pH of the water.
- Check that there is enough chlorine
The dose of chlorine is also very important. In sufficient quantity, this product disinfects, fights bacteria and blocks the appearance of algae. To ensure quality bathing water, a good dose of chlorine is key.
Discover everything you need to know about chlorine to keep your pool clean!
Trick: A chlorinator is a device that diffuses chlorine regularly in the pool water. Very useful, since it works autonomously and without electricity.
It represents an investment of €100 to €300, and will save you from having to regularly refill your skimmer with chlorine tablets.
Don’t forget to regularly test your water every week.
Monitor the operation of the filtration system
Ultimately, the quality of your pool water depends on how well the filtration system works. Make sure it works properly and, if necessary, clean the filters. This way you will avoid green or cloudy pool water.
How long does it take to get rid of green water?
Depending on the density of the treatment you have used, returning to crystal clear water may take more or less time.
An anti-algae shock treatment can restore transparency to the water in several hours.
A milder treatment, whose active ingredient is hydrogen peroxide, for example, can take up to 48 hours before taking full effect. If you have any questions, do not hesitate to consult the instructions for use of the treatment used.
As a general rule, the more intense the green color of the water, the more treatment it will need to combat it. A translucent green water can also come from a problem of corrosion in the pipes.
We advise you to carry out continuous maintenance of the pool and acquire a robot vacuum cleaner if necessary.
Can we bathe in a green water?
We are sure that you have asked yourself this question: We advise against bathing in a pool of green water. A water that has changed color, has suffered a proliferation of microorganisms and other polluting elements. The water does not have optimal conditions for bathing and can pose risks to your health. Conjunctivitis, otitis, skin irritation or gastroenteritis, the organisms present in contaminated water can be responsible for infections of all kinds.
A regular cleaning plan will help prevent the appearance of these microorganisms that can cause the green color of your pool water. You can also entrust the care and maintenance of the water to a professional. You can enjoy your pool, in clear and transparent water with nothing to fear, yes, it has a price.