The Science Behind the Salt Water Pool

The saltwater pool or saltwater chlorinated pool is a popular alternative to the more traditional chlorine pool - and with good reason. The water of a saltwater pool is gentle on the skin, kinder to sensitive eyes and has a softer, silkier texture. In addition, saltwater chlorinators limit exposure to the harmful by-products of chlorine and chlorine gas. In this article we’ll take a closer look at exactly how a saltwater chlorinator works and why it might be a better option for your Riverhead, NY pool.

What does chlorine do?

Chlorine is used to purify water and does so extremely effectively. It does this by reacting with water to form a number of chemicals including hypochlorous acid (a weak acid consisting of one chlorine molecule, one hydrogen molecule and an oxygen molecule - HOCl). This acid kills bacteria by essentially destroying the fat molecules contained in their cell walls before dissolving the interior of the bacteria’s cells.

The Science Behind the Salt Water Pool Riverhead NY

How does a salt water pool clean without chlorine?

It’s a common misconception that the salt in a saltwater pool is what kills bacteria and keeps the water clean and free from algae. This is, in fact, not the case. A salt water pool does use chlorine, but in smaller quantities and only when needed. It does this by converting the salt in the water directly into hypochlorous acid (the weak, acidic form of chlorine that we spoke about earlier.) This ensures that there is not too much excess chlorine in the pool at any given time, and only in the form that is most effective at destroying bacteria.

Related: Best Pool Surrounds for Saltwater Pools

Why bother converting the salt?

Theoretically it is possible to keep bacteria levels low using salt, however, salt would be needed in absolutely massive quantities to inhibit bacterial growth - something close to the concentration of the dead sea which consists of around 1 part salt to 2 parts water. Instead, saltwater chlorination uses a very simple and cost effective method to ensure that only relatively small quantities are necessary in order to keep your pool sanitary.

Benefits of turning salt into chlorine instead of adding chlorine to your pool

One the biggest downsides to traditional chlorine pools is no doubt the sharp smell and eye irritation caused by the chlorinated water. This is caused by an excess of chloramines, which happens when there is too little free available chlorine, or hypochlorous acid, to sanitize the pool. This would be solved in a traditional chlorine pool by adding a large amount of chlorine and “shocking” the pool. In saltwater pools, however, free available chlorine is constantly being produced, keeping the pool clear and algae-free, and burning off chloramines without the need for shocking the pool.

Related: Is a Saltwater Chlorinator Safe for Gunite Pools?

How is the salt turned into chlorine?

Saltwater pools filter the water through chlorinator cells which contain conductive metal plates. These cells run a current through the plates, causing the sodium chloride (NaCl), or salt, in the water to undergo electrolysis, converting it to hypochlorous acid. The process can cause the pool water to become alkaline over time, calling for the addition of an acid to neutralize it. On the upside, the alkaline solution is converted back to salt, ready to undergo electrolysis again.