What is a salt chlorination water treatment? Pros and possible Cons

Salt Chlorination is a method that adds salt (NaCl or sodium chloride) to the swimming pool in order to treat the water. The salt level on the water should be between 4 and 6g/l, being a similar concentration of salt that humans have on tears, therefore swimmers almost don’t perceive the salt on the water.

Once the salt is dissolved on the water, this element enters on the filtration cycle, where the chlorination system has the conversion cells to proceed with the electrolysis of the salting water. On this process, the elements of salt are separated, obtaining sodium (Na) in one hand, and Chlorine (Cl) on the other. The liberated chlorine is presented in gaseous state and is recombined with water, generating hypochlorous acid, which is the agent that disinfects the water of our swimming pool, being the same process as adding liquid or tablet traditional chlorine.

The hypochlorous acid disinfects the water, eliminating any pathogen elements such as viruses, bacteria, algae, etc. Afterwards, the chlorine combines back with sodium, resuming the process indefinitely. In order to form the hypochlorous acid it is fundamental to put an eye on the swimming pool pH, which must be between 7.1 and 7.3.

Salt chlorination main advantages

  • The main advantage is the economical, since the natural production of chlorine make us safe in terms of water treatment products, as well as in maintenance costs.
  • The salting water avoids the creation of bacteria and algae, working upon the skin of swimmers as smooth as natural antiseptic. The low salting concentration avoids ocular and dermatological pains produced by traditional chlorines.
  • Indirect chlorine manipulation, since the user does not need to be in touch with chemical chlorine.
  • Higher water disinfection due to the action of chlorine and other elements liberated during the salt electrolysis, avoiding the appearance of algae and bacteria.
  • Resulting water quality is much higher than the one we get with traditional chlorine treatments. The bothering pains made when chloramines make contact between the chlorine and organic matters, being one the mains reason why swimmers have irritation on skin and eyes, and the disgusting chemical odour around a swimming pool disappears.  

Salt chlorination possible disadvantages

  • The use of slat chlorination systems on a swimming pool has more advantages than disadvantages, nevertheless, we must pay attention on the pH levels of the swimming pool. The salt by itself increases the pH on water, so we should make pH checks more often.
  • Although the salt chlorination equipment can control and check the water parameters (chlorine, salt, pH, …), it is highly recommended to check pH and free chlorine on water at least twice per week, even when the swimming pool is out of use, and specially whenever we notice that the water is not as it should be. As soon as we check that parameters are on the correct levels, we will make sure that the system is working properly.
  • Conversion cell cleaning. Every 30 or 45 days we should check that the conversion cell is clean and in correct conditions. When the cells are not in proper conditions the most common consequence is that the water parameters vary from the correct range, this can turn into irritation on swimmers (eyes and skin) when pH is over the parameters, and algae generation when pH is below right parameters. The Chlorine variations can be harmful for swimmer’s health and on the other hand it makes a cost overrun on water treatment products and procedures, as well as the impossibility to use the pool until the parameters gets back to the correct range.
  • In case of we need a shock treatment, we will need to support the salt chlorination with traditional chlorine, since the salt chlorination does not allow a massive chlorine production required for this high-chlorine treatment.

Apart from the common maintenance jobs done to traditional chlorine treated swimming pools, salt chlorination pools need additional maintenance jobs:

  • Periodical salt concentration check and adjustment, which should be kept between 4 and 6g/l (depending on the manufacturer recommendations). The loss of salt only happens when we put out water from the basin, for example, when we clean the filtration system, never due to water loss by evaporation.
  • Periodical check and clean of lime on the conversion cell. The lime accumulation on cells reduces the life of those fundamental elements on the salt chlorination system.
  • Special attention to pH level, always between 7.1 and 7.3.

We should make a very special remark to those users with covers on swimming pools with salt chlorination system. Any time that the swimming pool will be covered for a long period such as winter, THE SALT CHLORINATION SYSTEM MUST BE SWITCHED OFF. The cover does not allow the evaporation of the generated chlorine, as a consequence, this chlorine liberated will stay between the waterline and the cover, and the membrane can be totally decoloured.

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