General introduction

In general, salts can be either edible or technical. Based on their structure, we further distinguish between rock salts (halite, mined in quarries) and sea salts (obtained from brine after water evaporates).

Then we distinguish between natural salts, i.e. with admixtures of other salts and other chemicals, and refined, purified salts, which contain almost pure sodium chloride.

Elements in salt (NaCl)

Rock salt

  • The most common mineral in salt deposits.
  • Contains almost 40% sodium (Na) and 60% chlorine (Cl).

Sea salt

  • Obtained by evaporating sea water.
  • The obtained raw material contains 80% halite and must be chemically purified to separate undesirable content (mostly magnesium sulphate, chlorine, sodium, sulphur, and magnesium).

Salt, electrolysis, and water disinfection

Salt for pools is used to disinfect pool water by electrolysis using the electrodes of the saltwater system.

The chemical reaction enriches the water with natural chlorine, which kills all living microorganisms and algae in the water. If these organisms were not eliminated, the water would turn green over time, would start to smell, and a layer of slime would form on the pool walls.

Salt electrolysis ensures clean and clear water in the pool, which is pleasant for swimming. Water is treated with naturally derived chlorine.

Why use the purest salt possible

Pure salt (at least 99.8%) added to the water at the prescribed dose and the chlorine derived from the salt will soften the water and disinfect it. With pure salt, you will not be adding other minerals to the water and will avoid causing additional problems when you operate your pool, saltwater system, or whirlpool.

Elements added to the water along with untreated salt can cause the following issues:

  • Iodine – salt with iodine content turns the water dark red after electrolysis (extreme case).
  • Calcium - causes hardness of water, deposits on the internal parts of the saltwater system, clogs the filter.
  • Magnesium – causes hardness of water, deposits on the internal parts of the saltwater system, clogs the filter.
  • Iron – colours the water red-brown, deposits on the bottom, clogs the filter.

For that reason, read the details on the salt packaging and only use salt with 99.8% purity.

We recommend buying exclusively pool salt certified for use with saltwater systems (Biocidal Product Certificate) EN 973:2009 Type A, EN 14805:2008 Type 1, Regulation (EU) No. 528/2012 concerning biocidal products.

For similar reasons, do not add any oil additives, perfumes, bath salts, pure magnesium, etc. to your pool or whirlpool. It is recommended to thoroughly wash sweat and sunscreen off your body before entering the water.

According to the manufacturer, saltwater systems produced from 2025 use improved technology that allows users to use regular table salt, salt with iodine content, and naturally evaporated sea salt.

Our recommendations and guidelines

Based on our many years of experience, we recommend using pure pool salts described above despite various improvements.

Water hardness over 25°N is high and means that inner parts of your equipment will clog and the electrodes will coat with sediment, leading to malfunctions. The water must be softened.

Water hardness up to 15°N is acceptable and there is no need to address water hardness.

It is recommended to clean the electrodes in acetic or citric acid solution one or two times a year, even under favourable conditions. Improve the cleaning effect by heating the solution to 25-30°C.

The benefits of using salt water and a saltwater system:

  • The process described above produces natural chlorine.
  • The water is treated gently, making it also suitable for children and for people with sensitive skin. Conventional chlorine tablets are much more aggressive.
  • The salt concentration in the water is so low that your eyes will not burn and you will not feel it on your tongue as well.
    • SALTWATER SYSTEM: 3 kg salt per 1,000 litres of water
    • SEA WATER: 35 kg salt per 1,000 litres of water
  • Save money – salt does not evaporate, therefore you do not have to replenish it all season long if you take good care of your pool or whirlpool water. Regular chlorine tablets or other chemicals need replenishing and handling them can be dangerous.