Calcium Hypochlorite

Also Known As:

A chlorine compound, calcium hypochlorite is used to keep pool and spas disinfected and clear of any contaminants. It kills and prevents the growth of algae, bacteria and other microorganisms.

The compound is used as a routine chlorinator, as well as a shock treatment, and will improve water clarity. In more concentrated forms, calcium hypochlorite is a disinfectant for cleaning the pool water, pool decks and walking surfaces, diving boards and ladders. Unlike its slippery counterpart, liquid chlorine (sodium hypochlorite), calcium hypochlorite is safe for pool decks at 64 percent concentration. Another advantage is that it won’t cause problems if it is carried into the water on swimmer’s feet or bodies.

Because calcium can increase hardness, clogging filters and causing scaling, anti-scaling agents may be added to some calcium hypochlorite products. The water should be tested monthly for calcium hardness.

In granulated and tablet forms, calcium hypochlorite is harmful if swallowed and may cause chemical burns. For that reason, these forms should not come in contact with the skin, eyes or clothing. It should also not be inhaled. Safety regulations mandate that the chemical be stored in its original, clearly labeled container, in a cool, dry, well ventilated area. Keep the lid tightly closed when not in use. Transfer the chemical with a clean, dry plastic or metal scoop that is used only for this purpose.

Calcium hypochlorite is highly flammable and should be added only to water. It should not be mixed with other pool chemicals, and its containers should not be reused for any reason.