Your test strip tells you what is wrong. This tells you how much to add.
Every pool guide says alkalinity should be 80–120. None of them says how many pounds of baking soda that is for a pool your size.
So here is the other half. One page, every common correction, worked out from 5,000 to 30,000 gallons — chlorine and saltwater. Print it and keep it by the pump.
- Chlorine — routine top-up and shock, cal-hypo and liquid
- Alkalinity, pH, hardness, stabiliser — amounts, not ranges
- Your gallons in five minutes — every pool shape
- Green, cloudy, stained, smelly — the one thing to do first
One page. US Letter. Free.
Where the numbers come from
Commonly accepted values from published public-health guidance — the Indiana Department of Health’s Adjusting Chemical Levels in a Swimming Pool and Yakima County (WA) Public Health. Sources are printed on the card.
The label on your container is always the instruction. Concentrations differ by brand and by year. The card is the arithmetic that gets you close; the label confirms the amount.
Where it came from
The card is one page out of Pool Maintenance, Open to Close — a season-by-season guide built around the same idea: never a target without an amount. Opening, the weekly routine, green water, closing and winter.
The card is free and stays free whether or not you ever buy the book.