Pool Alkalinity Calculator
Calculate how much sodium bicarbonate (baking soda) to add to raise your pool's total alkalinity. Dosing constant (1.5 lbs per 10,000 gal per 10 ppm increase) verified against ARM & HAMMER pool alkalinity guidelines and pool chemistry references (June 2026).
Alkalinity Inputs
Recommended range: 80–120 ppm
Dosing Reference Table (68% Cal-Hypo equivalent: Baking Soda)
| Pool Size | Raise 10 ppm | Raise 20 ppm | Raise 40 ppm |
|---|
Constant: 1.5 lbs sodium bicarbonate per 10,000 gal per 10 ppm increase. Source: ARM & HAMMER Performance pool alkalinity calculator — verified June 2026.
Formula
- 1.5 — pounds of sodium bicarbonate that raises 10,000 gal by 10 ppm (industry constant)
- ppm increase ÷ 10 — scales the constant linearly with the desired rise
- Pool gallons ÷ 10,000 — scales the constant to pool size
Related calculators: Salt Calculator · Shock Calculator · Chlorine Calculator · Stabilizer (CYA)
Frequently Asked Questions
The recommended range is 80–120 ppm for most pools. Alkalinity acts as a pH buffer — too low causes pH to swing unpredictably, too high makes pH difficult to lower and can cause cloudy water.
Approximately 1.5 pounds of sodium bicarbonate (baking soda) per 10,000 gallons raises total alkalinity by 10 ppm. This is the industry-standard rule of thumb used by pool professionals.
Yes. Pool-store "alkalinity increaser" is chemically identical to grocery-store baking soda (sodium bicarbonate). The only difference is packaging — grocery-store baking soda is typically more economical per pound.
Use muriatic acid (hydrochloric acid) or dry acid (sodium bisulfate) to lower both pH and alkalinity. Add acid with the pump running, broadcast it across the pool surface, and retest after 4–6 hours.
Yes — always adjust total alkalinity first. Since alkalinity buffers pH, correcting alkalinity will stabilize pH and often reduce the amount of pH adjustment needed.