I added Calcium Chloride because my 2015 TFT test kit said my CH was 225. But after adding I tested with my new 2016 TFT test kit and it was 425 (even though Pool Math said it should go to 325). I then retested with my 2015 test kit and it read 325. I am assuming the 2016 test kit is right but should I get a third opinion? I kept my 2015 kit on a table in our sun room (with a lot of windows) over the winter. It gets colder there then the rest of the house in the winter, but that room still gets heat, and gets a little hotter in the summer because of all the windows.
If the 425 reading is correct, I am concerned that I could get scaling if my PH rises too much. My pool is one year old and gets a lot of aeration. Will scaling result only if my CSI number falls out of the acceptable range or could a high PH and 425 CH cause it no matter what. My CH did not rise last year at all except when I added calcium chloride, so I was hoping to not have to worry about it, but am now concerned it may be a problem because it is on the high side now and my Polaris seemed to be picking up calcium (looked like crushed snow) when I opened this year (although my CH was not rising at all according to my 2015 test kit).
p.s My CYA is 30 and my TA is 60