I usually test my own water, but just for grins I took a sample to my local pool store and they used their "electronic analysis machine" to test it. The CYA reading from their test came back at "19," however when I've been checking on my own (about once a month) with the R-0013, it shows my CYA level is at about 60. Is it possible that my R-0013 is old/expired ? (I've had it for about two years -stored in a tight container in a cool, no- sun location). Or does their fancy machine need recalibrating?
Just wondering if anyone has had experience with pool-store water testing.
In addition, their ALK test for my water came out as 49, but I'm getting a consistent personal reading of 100 (using Taylor 07/08/09 reagents).