This is a printed lookup, not a calculator — there are no inputs and
nothing is computed. Read the band you need, then read the dose row;
the chart never does the multiplication for you.
Adjustment order matters. Balance in the order
printed across the top — Alkalinity → pH → Calcium Hardness →
Sanitizer (chlorine) → Stabilizer (CYA) — because each step shifts
the next reading.
Scale the dose to your pool. Every dose is per
10,000 gallons. Multiply by
(your pool gallons ÷ 10,000) in your head — a 20,000-gal
pool needs roughly double, a 5,000-gal pool roughly half. Add one
chemical at a time with the filter running, wait ~20 minutes, then
re-test before the next addition.
To compute the exact dose for your pool from a current and target
reading, use the dosing calculators linked below — that math lives
there, on purpose.