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Chemical Dosing Calculator (Comprehensive)

Calculates precise chemical amounts needed for all five major pool parameters: free chlorine, pH, total alkalinity, calcium hardness, and cyanuric acid.

Work out any chemical dose

Try an example

How it works

  • Free Chlorine: (Target FC - Current FC) × Pool Vol ÷ 120000 = lbs
  • pH: varies (6.4 fl oz per 10k gal lowers pH 0.1)
  • TA: 1.5 lbs per 10k gal raises TA 10 ppm
You enter
Pool volume (gallons), chemical type, current level (ppm), target level (ppm), chemical form (liquid/powder/granular)
You get
Chemical amount (fl oz or lbs), product type recommended, application method

How accurate is it? Assumes complete water circulation after 4-6 hours; different chlorine forms have different strengths; no chemical removes CYA (drain required).

These are estimates, not quotes. See How We Estimate.

Worked example

20,000-gallon pool: FC test shows 0.5 ppm, target 2.5 ppm. Using 12.5% liquid chlorine: (2.5-0.5)×20000÷120000 = 0.33 lbs needed.

Tap an example above the calculator to see it worked with live numbers.

Reference table

ProductPer 10,000 gallonsChanges
Liquid chlorine (12.5%)10.2 fl ozFree chlorine +1 ppm
Cal-hypo shock (65%)2 ozFree chlorine +1 ppm
Dichlor (56%)2.7 ozFree chlorine +1 ppm
Muriatic acid (31.45%)about 12 fl ozpH −0.2 (at TA 100)
Soda ashabout 6 ozpH +0.2 (at TA 100)
Baking soda1.5 lbAlkalinity +10 ppm
Calcium chloride (77%)1.25 lbCalcium hardness +10 ppm
Stabilizer (CYA)13 ozCYA +10 ppm
Pool salt0.83 lbSalt +10 ppm

When to use it

Ensures safe, balanced water chemistry by providing exact dosages in proper adjustment order (TA→pH→Calcium→CYA→Chlorine).

Weekly water testing and treatment, addressing chemical imbalances, opening/closing pools, emergency algae treatment.

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Reference pages