Thanks for the response, Richard. The TA tested out at 100ppm and is supposed to be 120-150 according to the guidelines for my spa. It had been 120 ppm before I added the Ph decreaser. The Ph has been 7.8 or higher for a while, regardless of the decreaser I add.
For my chlorine and shock regimen, I add 1 cap chlorine every other week and 1 cap non-chlorine shock every week. The spa has a vision cartridge (silver) and an ozone filter. I was told this would help lessen the need for sanitizers. Should I keep trying to bring the Ph down even if the TA will go lower than recommended. Should I add decreaser every other hour or every other day until it reads properly. Thanks.
I am fascinated by your water maintenance. If you've had your tub since May and haven't had any problems with water quality, that's unreal. I know that the companies that manufacture the silver cartridges suggest low chlorine, but they usually recommend daily dosing with mps. How often do you soak and how many people usually soak? How long have you gone between water changes. Sorry to give you the 5th degree, but this is interesting.
I forgot to ask what temperature the spa should be set at when I am away on business. I have been leaving it at 99 degrees all winter, 24/7 and adding sanitizers in between trips.