Tested my tap water as well as the tub today just out of curiosity.
pH seems to be about the same at around 6.8-7.0 at best for both despite my use of 1 TBS of baking soda yesterday morning. The TA was very low for the tap water but about 120 for the tub which seems to be about where it was before the baking soda, maybe just slightly darker than before.
No chlorine reading in either after using a single tsp of dichlor last night. And the CA still seems to be reading low in both (The strip calls this one "stabilizer" and I am just guessing it measures CA.
Probably try to refrain from messing with it for a few days while the service tech comes out to evaluate the error message I keep getting for "power board communication". Dealer suspects the secondary control pad on the opposite side of the tub.
Hasn't seemed to affect spa function so far but disconcerting none the less.