The disinfecting power of this compound comes from chlorine. Commercially available varieties generally contain 65% to 75% chlorine. It also adds around 0.8 parts per million (ppm) of calcium to your pool water for every 1 ppm of free chlorine (FC), or the chlorine actively available to sanitize your pool, you add. Be sure to plan accordingly if your water already contains a high concentration of calcium.

hen calcium hypochlorite encounters microbes and other organic contaminants, the chlorine compounds it contains will disrupt the functions of their cells by bonding with enzymes and other cell components. This will shut down the bacteria by disabling its internal workings or destroy it by rupturing the cell walls, sanitizing your pool water.

When chlorine bonds with organic compounds, it becomes captured chlorine (CC). Your pool's total chlorine is the sum of its FC and CC.

Just make sure you add cal hypo to your pool at dusk, and you can wake up to a sanitized pool.