Salt water treatment requires the installation of an electrolyzer. This is a more costly initial investment than with other water treatments such as bromine or chlorine. In recent years, however, it has become increasingly popular with pool owners (30% of the market in France). In fact, a salt pool is more ecological and economical in the long term. Families with young children appreciate the bathing comfort of salt. If you're not sure how to treat your pool, read this article to find out.
How does salt pool treatment work?
Choosing a salt treatment to disinfect your pool water requires the installation of an electrolyzer. This is an electrical device that connects to the filtration circuit located in the technical room. Sea salt injected into the water is transformed by electrolysis into sodium hypochlorite, i.e. unstabilized chlorine. The electrode permanently and regularly breaks down the salt in the water into natural chlorine and caustic soda. When the chlorine has disinfected the water, under the effect of the sun's rays, it becomes salt again, recombining with the caustic soda. Then the cycle starts all over again.
Thanks to this process, chlorine, produced in small quantities, effectively eliminates micro-organisms and bacteria present in the water.
Unlike chlorine or bromine treatments, salt water treatment requires a higher initial investment. The cost of an electrolyzer varies between €800 and €3000, depending on the model. You can choose from an entry-level chlorinator that needs to be activated manually, to the most sophisticated models (automated and connected to the Internet) that can be controlled from your smartphone.
Salt-based pool treatment has only been popular in France for a few years now, but it's now a popular choice for pool owners all over the world.
The advantages and disadvantages of treating your pool with salt
Benefits
Easier and faster to use : the chlorinator produces chlorine and injects it into the water automatically. This saves time compared with other treatments, which require regular product additions. Salt replenishment is also less frequent: once at the start of the season, and again in summer if necessary. Quantities vary, of course, according to the volume of your pool and the model of your chlorinator.
Healthier for skin and mucous membranes, odorless: unstabilized chlorine, produced by the transformation of salt into chlorine, is more comfortable for the skin. If you have fragile skin, young children or a high level of allergies, salt treatment is the right choice for you. What's more, stabilized chlorine is odorless (like bromine).
More environmentally-friendly treatment: the sea salt injected into the electrolyzer is a natural product. It doesn't pollute and doesn't require the purchase and addition of chemicals to the water. This is a huge advantage, as it means you can enjoy your pool every day, without having to wait 24 or 48 hours before taking a dip. What's more, if the pool needs draining, there's no need to treat the drained water.
More safety. Salt is also interesting because it's safe to store chemicals. If you have pets that may drink from the pool, salt treatment is still the least dangerous for them (even if it's not recommended!).
Disadvantages of salt water chlorinators
Despite its real ecological and safety advantages, salt treatment has a few constraints that you should be aware of:
Higher pH levels With a salt water chlorinator, the pH tends to be naturally higher. Indeed, the caustic soda produced during electrolysis tends to raise the pH level. The ideal pH is between 7.2 and 7.6 The pH must be tested very regularly (at least twice a week in high season), and a high-performance filtering system must be chosen. pH regulators are available on the market and can help you regulate it more effectively.Everything to know about pH.
Temperature sensitivity As soon as the water temperature drops below 17°C, you need to go into winter storage to preserve your electrodes. The end of the summer season may therefore be a little shorter than with other treatments. Alternatively, you can add equipment to heat and maintain water temperature. If the water temperature is too high, the chlorinator will produce more chlorine.
Salt corrosion and regular maintenance: Beware of the corrosive power of salt! The maintenance of your pool must be carried out with great regularity, in particular by cleaning the electrodes every 6 months. If you can, we recommend purchasing a self-cleaning chlorinator.
A higher upfront cost The purchase and installation of an electrolyser has a fairly high initial cost (on average 1,500 euros). However, the investment pays for itself in just a few seasons, as the cost of salt remains the lowest. Lastly, consumption of other products is much lower. You need to change the electrodes every 3 to 4 years, as they oxidize.
Electrolyser failures or anomalies: The chlorinator can produce too much or too little chlorine. It is therefore essential to regularly check that it is working properly.
Measuring salt in your pool
Optimum salt level in the pool
To ensure that the chlorinator works properly and produces the right amount of chlorine, add salt at the start of the season.
The optimum salt level is between 3,000 and 5,000 ppm (or 3 to 5 g/L).The threshold depends very much on the model of your chlorinator, so refer to the manufacturer's instructions.
To start with, you add the right amount of salt according to the volume of your pond. Here's the calculation method you need to know. Recommended salt rate x Pool volume = Quantity of salt to be added to the pool. Here's an example:
recommended salt level = 5g/L
Volume = 28 m3 soit 28 000L
Quantity of salt = 140,000g, i.e. 140 kg
How to measure the salt level in your pool?
There are three solutions for measuring salt concentration in water:
Salt treatment-specific test strips It measure salt concentration and, by colorimetric reaction, give an indicative value for the salt content of water. Although this method is the least expensive, it is not very accurate. As with the salinometer, it's preferable to measure a sample of water rather than immersing it directly in the pool.
The salinometer or conductimeter: This electronic sensor, once immersed, measures the salt level and indicates the result on its digital display. It is advisable to take a sample of water (20-40cm underwater) in which to immerse the sensor. The average price is 50 euros.
A connected water analyzer with a TDS (Total Dissolved Solids) probe: TDS probes are generally integrated into connected water analyzers, salt version, such as ICO Pool. It automatically analyzes several water parameters (pH, disinfectant and TDS). This all-in-one solution is highly appreciated by pool owners. It saves you from having to invest in several measuring tools. Read our article All you need to know about TDS.
Check salt levels regularly. Particularly after heavy rain and in the days following the addition of salt, to check that it is converting properly into chlorine and soda.
What you need to know about salt pools
Salt electrolysis for swimming pools is the most environmentally friendly of all treatments. If you have young children or allergy sufferers, it's certainly the right choice for you, especially as the storage of sea salt represents no danger. However, you should be aware that this is an option that requires more monitoring (water temperature, electrolyzer operation, pH ). We recommend investing in automated equipment for testing water parameters, for greater peace of mind.
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