You can go online at Costco.com and apply for a Costco Membership there by adding it to your shopping cart if you are shopping for the first time. Your membership card will be mailed to you within 7-10 days but you can actually shop at the online store immediately.
The three most common chlorine-containing substances used in water treatment are chlorine gas, sodium hypochlorite, and calcium hypochlorite.
As a mixture with lime and calcium chloride, it is marketed as chlorine powder or bleach powder for water treatment and as a bleaching agent. This compound is relatively stable and has greater available chlorine than sodium hypochlorite (liquid bleach).It is a white solid, although commercial samples appear yellow.alcium hypochlorite is an inorganic compound with formula Ca (Cl O) 2.