How much chlorine for a 40,000 litre pool
To raise chlorine by 1 ppm in a 40,000 litre pool (40 m³), use about 62 g of 65% chlorine granules, 71 g of 56% stabilised chlorine or 333 mL of 12% liquid chlorine. Keep free chlorine between 1 and 3 ppm.
Chlorine: amount to raise free chlorine
| Product | +1 ppm | +2 ppm | +3 ppm | Shock (+10 ppm) |
|---|---|---|---|---|
| Granules (calcium hypochlorite) 65% | 62 g | 123 g | 185 g | 615 g |
| Stabilised granules (dichlor) 56% | 71 g | 143 g | 214 g | 714 g |
| Liquid chlorine 12% | 333 mL | 667 mL | 1 L | 3.33 L |
| Household bleach (unscented) 5% | 800 mL | 1.6 L | 2.4 L | 8 L |
Other products
| Goal | Product | Amount |
|---|---|---|
| Raise alkalinity by 10 ppm | Buffer / alkalinity increaser (sodium bicarbonate) | 720 g |
| Raise stabiliser (CYA) by 10 ppm | Cyanuric acid | 400 g |
| Salt from 0 to 3,200 ppm (chlorinator) | Pool salt (no iodine) | 128 kg |
| Weekly maintenance in a floating dispenser | 200 g chlorine tablet | 2 tablets a week |
Calculate with your readings
The calculator below already has this pool's volume. Enter what your test showed to get the right dose of each product.
Result
Estimate. Check the product label (if it differs, follow the label), add one product at a time and test again before anyone swims.
How to add it
- Test free chlorine, pH and alkalinity with a test kit.
- Fix alkalinity first, then pH, and chlorine last.
- Dissolve chlorine granules in a bucket of pool water and spread it around with the pump running.
- Wait 4 to 6 hours with the filter on and test again before swimming.
Safety
- Never mix different products, dry or dissolved. Add one at a time, with a gap in between.
- Dissolve granules in a bucket of pool water before adding them. Always add the product to water, never water to the product.
- Wear gloves and eye protection when handling acid and chlorine. Store away from children and out of the sun.
- These are estimates for home use. Always follow the manufacturer's label and test again after dosing.
In case of an accident: call emergency services (000 in Australia, 111 in New Zealand, 999 in the UK) or the Poisons Information Centre (13 11 26 in Australia), and bring the product container.
Frequently asked questions
How many grams of chlorine for a 40,000 litre pool?
To raise it by 1 ppm, about 62 g of 65% chlorine granules. For daily maintenance, usually 1 to 2 ppm.
How many chlorine tablets for a 40,000 litre pool?
As a starting point, 2 tablets a week (200 g), always in a floating dispenser, never directly in the pool. The amount varies by brand: check the label. Tablets only maintain chlorine; for green or cloudy water, use granules or liquid chlorine.
How much liquid chlorine for a 40,000 litre pool?
About 333 mL of 12% liquid chlorine for each 1 ppm.
What about household bleach?
With household bleach at 5%, about 800 mL for each 1 ppm. Only use unscented bleach and check the % on the label.