Patent ID: 8372291

Claim:
A method of treating recreational water, comprising the steps of: (1) adding to said recreational water a granular water treatment composition comprising: 35 to about 90 wt% calcium hypochlorite; 10 to 50 wt% magnesium sulfate or a hydrate thereof; 0.5 to 5 wt% lime; and 1 to 37.5 wt% of a water soluble zinc salt or a hydrate thereof; all weight percents based on the total weight of said composition; followed by (2) adding to said recreational water one or more water treatment tablets comprising: 35 to about 85 wt% calcium hypochlorite; 15 to about 40 wt% magnesium sulfate or a hydrate thereof; 0.5 to 5.0 wt% lime; and 0.5 to 10 wt% of a water soluble zinc salt or a hydrate thereof; all weight percents based on the total weight of said tablet.