[M2inOR]

I'm no pool expert, but Google helps:

I saw several bags of calcium hypochlorite next to the pool filtration equipment at the Cattail pool. Here are some facts about the chemical:

Fast-acting Calcium Hypochlorite chlorine granules provide 68% available chlorine for your pool.

Granules can be used in swimming pools, spas and hot tubs.

Provides powerful, effective sanitizing power for all needs.

Kills bacteria, algae and other organic contaminants.

Clears cloudy water or dull water appearance.

Suitable for residential or commercial pool treatment.

Vinyl pools should pre-dissolve Cal-Chlor into a bucket of water.