EPA instructions for preparing calcium hypoclorite solution for disinfecting water.
http://water.epa.gov/drink/emerprep/emergencydisinfection.cfm#tabs-2
Note...calcium hypoclorite is very corrosive. Read up on the care and storage of this stuff...a sealed glass container might be the best. If the container is not leak-proof...the fumes will rust nearby metal objects.
Good price - and free shipping!
How do you store yours? cI had some in a plastic bucket before I moved. I never noticed any deterioration of the bucket.
Half gallon mason jars would work with plastic lids, I guess.