This article is from ZodiacPoolCare.com

The Most Frequently Asked Questions About Zodiac Salt Water Chlorination

Zodiac is often asked to explain how a chlorinator works, how the chlorine is produced, and how it is different from the chlorine which is available in the form of granular chlorine, liquid chlorine, or chlorine tablets. The following information is presented in a question/answer format to cover the most frequently asked questions by engineers, swimming pool operators, or perhaps swimming pool owners.

All the commercial production of chlorine gas throughout the world uses the same basic technology as used by Zodiac salt water chlorinators.

IS THE CHLORINE PRODUCED BY A SALT WATER CHLORINATOR DIFFERENT TO THE CHLORINE IN GRANULAR CHLORINE OR LIQUID CHLORINE?

Sanitizing a pool with a Clearwater Technology salt water chlorinator uses a similar technique as sanitizing the same pool in other chlorine forms. The most common form of chlorine used for manually sanitizing pools is either granular chlorine, or sodium hypochlorite (sometimes called liquid chlorine). Commercial pools which do not use a salt chlorinator use a variety of forms of chlorine, including chlorine gas.

Note that calcium hypochlorate contains 65% chlorine, sodium hypochlorite contains approximately 12.5% chlorine, but the chlorine produced by a Zodiac salt water chlorinator is 100% chlorine .

The chlorine produced by a Zodiac chlorinator is exactly the same element (chlorine) as is contained within sodium hypochlorite and calcium hypochlorate. In other words, the active sanitizing agent for all of these methods is the same....chlorine.

DOES A ZODIAC SALT WATER CHLORINATOR PRODUCE CHLORINE IN ANY DIFFERENT WAY TO THE PRODUCTION OF GRANULAR CHLORINE OR LIQUID CHLORINE?

Mass chlorine production in huge chlorine factories uses exactly the same basic technique as is used by a Zodiac chlorinator. This technique involves the passage of electric current through salty water to produce chlorine gas at the positive electrode (anode).

WHAT IS THE CHEMICAL REACTION AND FORMULA?

The chlorine produced by a Zodiac salt water chlorinator is a product of salt water. The process may be explained in chemical terms by the formula below.


(Salt + Water + Electricity produces Hypochlorous acid and Hypochlorite ions + Sodium Hydroxide.)

The formula does not mention chlorine gas, because the chlorine dissolves immediately as part of the reaction. (The elemental chlorine gas produced at the anodes in the electrolysis process dissolves immediately into the water to form hypochlorous acid and hypochlorite ions.)

This is the same chemical reaction as occurs at commercial chlorine manufacturing facilities.

It is the hypochlorous acid and to a lesser extent, the hypochlorite ions that perform the sanitizing function in the swimming pool.

HOW DOES THE ZODIAC CHLORINATOR PUT THE CHLORINE INTO THE WATER?

The Zodiac cell produces elemental chlorine gas in the water, and the chlorine produced is exactly the same as other types of chlorine used for swimming pool sanitization.

Regardless of whether the chlorine comes from the electrolytic action of a Zodiac cell, or from the chlorine contained in granular chlorine or liquid chlorine, the chlorine dissolves into the water to form hypochlorous acid and hypochlorite ions.

It is actually these two components which are the active sanitizers in pool water. Hypochlorous acid is a strong sanitizer and hypochlorite ions are a weak sanitizer. It is important that the pH of the water is correct to ensure a high proportion of hypochlorite acid, and therefore, the most effective sanitizing of the pool.

WHY IS ZODIAC SALT WATER CHLORINATION BETTER THAN TRADITIONAL METHODS?

The reasons why sanitizing using a Zodiac salt water chlorinator is better than other techniques are as follows:

a) Clearwater Technology chlorinators manufacture and deliver chlorine to the swimming pool automatically. The pool owner no longer needs to purchase, transport, store or manually add chlorine as part of their routine maintenance.

b) Not only is the water passing through the cell subjected to the sanitizing effect of the chlorine being introduced into the water, but as the water passes between the positive and negative electrodes, the bacteria, and algae are subjected to a very strong electric field which oxidizes these contaminants. These contaminants and others, including sunscreen, lotion, and body oils, etc are doubly attacked when using a Zodiac cell. They are destroyed not only by the chlorine in the water, but also by the electric field within the electrodes.

c) Zodiac manufactures and delivers chlorine to the pool in a constant and controlled manner. Because a Zodiac chlorinator is part of the filtration system, the sanitizing takes place every time the filtration system is switched on. There is less reliance on the human factor.

d) Say good-bye to red stinging eyes, skin irritation and harsh chemical odors. In general, whenever swimmers enter chlorinated water, chloramines are formed. This accurs because the body wastes, perspiration and skin oils all contain amine compounds which react with the chlorine in the water. If the chlorine only partly oxidizes (destroys) the amine compounds, "chloramines" are formed.

Chloramines are unpleasant smelling substances which sting the skin, cause eyes to become red and sore, and in extreme cases (high concentrations and allergic individuals), can cause skin rashes.

The major scientific benefit offered by salt water chlorination in the sanitizing process is that not only is there a sanitizing action in the swimming pool resulting from the free chlorine residual in the water, but there is a far more powerful sanitizing action which takes place in the cell itself.

As the water passes between the electrodes, the chloramines in the water are destroyed as they pass through the cell. Only a salt water chlorinator can destroy chloramines in this way.

e) When a Zodiac salt water chlorinator is used, there is more than an even dosing rate of chlorine. If for example the filtration system is operated 8 hours per day while the bathers are in the water, then the water is being sanitized continuously during the 8 hour period. The chlorine level remains at a satisfactory reading while the bathers are in the water.

WHY IS THE ADDITION OF CHLORINE STABILIZER (CYANURIC ACID) NECESSARY WHEN USING A ZODIAC (OR ANY OTHER) CHLORINATOR?

This chemical acts as a sunscreen for chlorine and prevents it from being too quickly destroyed by the sun. Chlorine stabilizer is essential to prolong the life of chlorine in the pool water. Although some types of chlorine (dichlor and trichlor) already contain stabilizer, the chlorine gas produced by a Zodiac chlorinator does not. Chlorine stabilizer cyanuric acid must therefore be added to the pool water when using any salt water chlorinating system

SUMMARY

A Zodiac salt water chlorinator does nothing more or less than produce chlorine. It is the exact same elements found in all other chlorine sanitizers.

Most importantly, a Zodiac salt water chlorinator produces chlorine automatically at the pool site. With a Zodiac chlorinator, the chlorine is made in the water, and stays in the water, and the electric fields within the electrolyte cell provide even greater sanitizing and oxidizing than if manually adding other chlorine compounds.