Soak only recommends what you actually have, and tells you the substitute when you are missing something.
Reader calibration
Color guide · built in
Sampled from AquaDoc's own published chart, so you never need the bottle in frame. Green underline marks the OK band. One caveat: AquaDoc's chart image repeats the alkalinity row in the pH slot — clearly a mistake, since the bottle prints pH as orange through red. pH here uses the standard progression instead, so it is the row most worth correcting.
Your spa
Doses are estimates for planning. The product label is always the authority — if the bottle disagrees with Soak, follow the bottle.