Pool Chemical Dosing Calculator

For standard 31.45% muriatic acid, use about 26 fluid ounces per 0.2 pH reduction per 10,000 gallons. This calculator scales that rate by your pool volume and the size of your pH drop automatically. For a 15,000-gallon pool dropping pH from 8.0 to 7.4 (a 0.6 reduction), that works out to roughly 117 fl oz, or about 0.9 gallons. Always add acid to water, never water to acid, and distribute it with the pump running.

Sodium bicarbonate (baking soda) raises total alkalinity at about 24 ounces per 10 ppm increase per 10,000 gallons. For a 15,000-gallon pool going from 60 to 90 ppm (a 30 ppm increase), that's roughly 108 ounces, or about 6.75 pounds. Baking soda is preferred over soda ash for alkalinity because it has minimal effect on pH.

Adjust pH first, then total alkalinity, then calcium hardness. Both alkalinity and calcium corrections can shift pH, so setting pH first reduces the number of re-corrections. Circulate the water and wait between additions — about 15–20 minutes after muriatic acid, 20–30 after soda ash, and 15 after calcium chloride — then retest before layering the next correction.

Not directly. Lowering total alkalinity requires adding muriatic acid to drop both pH and TA, then aerating to bring pH back up without raising alkalinity — often a repeated cycle, not a single dose. Calcium hardness can only be lowered by partial draining and refilling with lower-hardness water. This calculator flags both cases instead of giving you a dose.

It uses the same industry-standard rates a professional dosing engine uses, scaled to your volume. Real-world results vary with chemical concentration, water temperature, and test accuracy, so always retest after a turnover cycle before adding more. Treat the doses as a strong starting point, not a substitute for a reliable test kit.