I'm a new spa owner following the How do I use Chlorine in my Spa (or pool)? approach to maintenance. I'm also using the Pool Math app to log my upkeep and calculate any chem additions. I recognize the app is mostly for pool use, but is it possible to change a setting somewhere so that the recommended values are those for spas/hot tubs? Or is there some other means to customize the "Recommended" value ranges for the different parameters? Not a huge deal, it just means the little exclamation point icons aren't meaningful for me (though I'm starting to memorize the values noted by Nitro's post anyway).