Toedter says the ideal range for hot tub water pH and TA is 7.4 to 7.6 and 80 to 120 ppm, respectively, although this may vary slightly based on whether you use chlorine or bromine as a sanitizer.

On hot tubs you can get a little floating dispenser, and it just floats around on the water, just slowly releasing chlorine or bromine. There's also a chemical test kit, and on the left will be to ...