Unfortunately, we have found through the years that pool store testing is not usually very accurate. After all, they are in the business of making money by selling you stuff. It is better to test it yourself which is why I recommended that you get a good kit for yourself.

CYA is cyanuric acid, also called stabilizer or conditioner. It is kind of like sunscreen for your chlorine. Outdoor pools need some or else they quickly lose all of their chlorine to the sun. Needed chlorine levels are based on the CYA reading so it is important to know what it is. More info about the CYA/Chlorine connection can be found here:> http://pool9.net/cl-cya/