Welcome to our forum.
( once again I am typing slower than Windsurf :-) )
Maybe, I'm missing something!In pool chemistry (don't have a tub yet) if your Alkalinity is OK, your PH resists change. The amount of "stuff" you put into a tub is propotionately less than a pool, so if the PH is OK and the Alkalinity is in the proper range - the PH is kind of "locked in" and won't bounce all over the place. We will assume that the Calcium is correct also to give us balanced water.Is there something different to tubs?
It just so happens that I am a card carrying member of the Holiday Inn Priority Club, Thank you very much. :-/
Dude! This is WAY too coincidental.......did you by chance stay in a Holiday Inn Express last night?