I put up a new Intex Ultra Frame 16' pool in lat May/early June. I had researched using this site and had the Taylor test kit ready to go. Upon taking initial measurements on June 8th, I had a 7.1 pH, 40 ppm Alkalinity, 40 ppm Calcium, and 2 ppm Chlorine. That was the date I added CYA as well. The last test I did prior to coming back from a vacation was on 7/5 and I had a 7.2 pH, 110 Alkalinity, 90 Calcium, 6 ppm chlorine and 55 ppm CYA. When I tested this Sunday, 7/14, my measurements changed drastically with pH bottomed out and Chlorine at 0. I added some chemicals and as of tonight I'm at this measurement:
Chlorine: .5 ppm
Alkalinity: 160 ppm
Calcium: 120 ppm
I haven't retested CYA because I'm nearly out of the ability to test it, but I can if necessary. I was under the impression it shouldn't change much without a change in pool water of some kind. The SWG I'm using is 3 years old and an Intex brand but hasn't caused any problems in the past (although I wasn't testing this thoroughly with the good kit). Any advice? Thanks!