Calcium Hypochlorite, or Cal Hypo, is a dry form of chlorine that is available in both granular and tablet form. Calcium hypochlorite is 65 percent available chlorine, has a long shelf life, and is easily stored. A cool, dark storage place and a tightly secured lid will go a long way in extending its life.
In residential pools, calcium hypochlorite tablets are placed in erosion feeders or surface skimmers, where they are dissolved and disseminated throughout the pool. In some cases, you may use granular or powered chlorine, but it is best to dissolve it in water before distributing it into the pool. Many people keep granular calcium hypochlorite on hand for a variety of poolkeeping chores, as it kills algaie on contact and is useful in dissolving stains.
One disadvantage of calcium hypochlorite is that it is extremely flammable. Just about any organic material added to this type of chlorine will cause combustion. In fact, soda, oil, sweat, paper, soap, other chemicals, and almost anything else will cause a fire when mixed with calcium hypochlorite. For these reasons, it is imperative that you store calcium hypochlorite separately to prevent other chemicals and organic substances from accidentally mixing with it. The drums in which it is stored must be kept off the floor, and separate chemical scoops and buckets must be used when applying it.
Calcium hypochlorite is unstable, dissipating quickly in sunlight, although it can be stabilized with cyanuric acid to extend its life in the sun.
The Pool Pump • The Filters • Sand Filtration • D.E. Filtration • Cartridge Filtration
Water Chemistry • Popular Disinfectants • Chorine • Calcium Hypochorite • Sodium Hypochlorite • Stabilized Chlorines •
Bromine • Other Disinfectants • Water Balance • pH • Total Alkalinity • Calcium Hardness • Total Dissolved Solids •
Balancing Pool Water • Water Testing • Pool Vacs & Sweepers
Pool Maintenance • Daily Chores • Weekly Chores • Solving Common Problems • Cloudy, Milky Water • Malodorous, Irritating Water
Green Water • Red or Brown Water • Blue - Green Water • Blue or Black Water • Pump Problems • Sand in Pool •
Excessive Water Loss • Excessive Foaming