I'm hoping someone can help answer this question. I read that in order to lower TA a significant amount, that it needs to be done in stages. My well water is consistently 200-220 TA and 200 CA level. So when I do a fresh fill of my spa (385 gal), I need to lower my TA considerably. I've used dry acid in the past, but am now using muriatic acid. Other than the risk of overshooting it, why is it necessary to reduce the TA in stages (while keeping a target ph)? It's been my practice to add about 10 oz of muriatic acid at once (usually calls for about 13 oz) and then use dry acid to get to the correct balance of TA and PH. I never seem to have a problem with the PH or TA with my method. I dilute the acid in a bucket of spa water before adding it to my spa. Other than the risk of overshooting it, what other risks might I be facing by doing it this way. I read on elsewhere when it comes to reducing TA, patience is a virtue. That's not a virtue that I posses.