Water professionally tested and pH value was 7.5.
All other values were within guidelines. Spa dealer suggested SpaGuard Spa Sentry (1 qt) to lock in pH. Did that according to instructions. Used spa (two people) for three hours last evening, and chlorinated spa after use. Tested pH today at noon and the level was aprox. 8.2! Are we doing something wrong or is that a normal thing? Do we need to add a decreaser? We thought the Spa Sentry would keep the level the same.
Thanks for any help!