Pool Chlorine Calculator (How Much to Add)
Enter the pool volume, current and target chlorine, and the product’s strength.
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Pool Chlorine Calculator (How Much to Add) by TheCalcTools
How the Pool Chlorine Calculator (How Much to Add) works
One ppm is one milligram per litre, so raising free chlorine by Δppm needs Δppm × litres milligrams of chlorine. Dividing by the product’s available chlorine gives the amount: grams (or millilitres for liquid rated in trade percent) = Δppm × litres ÷ (10 × %).
Add chlorine with the pump running, away from metal fittings, and re-test after a few hours. Never mix different chlorine products.
The formula
Worked example
Using the default values shown in the calculator:
| Pool volume (US gallons) | 15000 |
|---|---|
| Current free chlorine (ppm) | 1 |
| Target free chlorine (ppm) | 3 |
| Product | Liquid chlorine (sodium hypochlorite) |
| Available chlorine of the product | 12.5 % |
- Raising 15,000 gallons from 1 to 3 ppm with 12.5% liquid chlorine: 908 mL (30.7 US fl oz).
Result:
| Amount to add | 908 mL (30.7 US fl oz) |
|---|---|
| Rise in free chlorine (ppm) | 2.0 |
| Pool volume (litres) | 56,781 |
| Side effect | Raises pH slightly |
Frequently asked questions
How much liquid chlorine raises 10,000 gallons by 1 ppm?
About 303 mL (10.2 US fl oz) of 12.5% trade-strength liquid chlorine.
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This calculator gives estimates for information only. Check important results independently before you rely on them. See our disclaimer.