Chem geek,
Thank you for the short chemical lesson. I get the part with the chlorine or Clorox. I am using 8.5%. Today I tested as follows:
FC=1, CC=1.5, TC=2.5, TA 130, CYA= 20+, CHLORINE= .5, PH=8.2. I added approximately 6 ounces of Clorox and added what came with the spa called PH Down...