What is Chlorine?

Chlorine in any form, mixed with water forms hydrochloric acid (HC1) and hypochlorous acid (HOC1), which is the killing form of chlorine. Its purpose is to kill bacteria in the water. Bacteria carry disease and stimulate algae growth. Chlorine sanitizes your pool by oxidizing the bacteria and other waste in the water. Oxygen is, in essence, dissolving the material with which it comes into contact. Sanitizers, oxidizing in your pool are essentially dissolving the bacteria and other waste material in the water.

Chlorine inactivates or kill the vast majority (above 99.9%) of pathogens and microorganisms that can cause disease. Pathogens include bacteria, fungi, viruses, and protozoan parasites.

Most common forms of Chlorine in Australia:

Sodium Hypochlorite (liquid)

Sodium Hypochlorite is a liquid chlorine. The convenience of feeding liquid and the relatively low cost, play an important role in its popularity. The hydroxide ion (OH-) reacts with the pool or spa water to raise the pH. The strength as used at the pool is approximately 13% available chlorine content (ACC) and has a pH of 13. Correcting PH by adding hydrochloric acid or the injection of C02 is necessary to ensure proper PH is maintained .

Calcium Hypochlorite (dry)

Calcium Hypochlorite is a dry form of chlorine often called “cal-hypo.” This is available in granular tablet, or briquette form. The ACC can vary from 50% to 78%, depending on the manufacturer. The amount of active ingredient and the ACC are the same with cal-Hypo. It is commonly used to super chlorinate water based on the high available chlorine content (65-78%) and its moderate solubility. One kg of premium grade cal-hypo, dissolved into 50,000 litres of water will increase the chlorine level by approximately 10 ppm.

Lithium Hypochlorite

Lithium hypochlorite is a dry, granular compound which is rapidly and completely soluble, making it a good choice for super chlorination. It is not widely used due to relatively low active strength of 29% (ACC 35%) and the relatively high cost. This product dissolves very quickly, making it ideal for use in vinyl-lined, fiberglass, or painted pools.