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.
Types of Non-Stabilized Pool Chlorine. Liquid chlorine (sodium hypochlorite) â popular in many parts of the country, has some complications in its use. It is only 10-15% available chlorine, and has more sodium than chlorine. It is the fastest acting due to the fact that it is pre-dissolved.