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.
Chloramine is a combination of chlorine and ammonia. When your municipal water supply uses Chloramine, you want to use a water conditioner which removes both chlorine and ammonia. Many of the water conditioners on the market ONLY remove the chlorine from your tap water leaving the harmful ammonia in your pond water.