Pools & water systems / Chemicals
Work out a pool chemical dose
Enter the pool volume, your test reading and the product you are using. See how much to add.
Dose
Raise free chlorine
Enter volume litres.
This does not cover pH. The right pH dose depends on alkalinity, so follow your pH product's chart.
How it works
Put in your numbers
Use your own rates, times and measurements.
See your answer straight away
It works it out as you type.
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Send it on, or keep it with the job.
What it covers: Work out how much chlorine, bicarb, calcium, stabiliser or salt to add from a test reading.
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How to work out a pool chemical dose
To work out a chemical dose you need your pool volume, your test reading and the strength of the product you are using. This calculator uses those to show how much product gives the rise you need. Always follow the product label and your test kit.
- Work out your pool volume in litres or US gallons. Choose metres for litres or feet for US gallons. If you are not sure, use the pool volume calculator first.
- Test the water and choose what you need to raise: free chlorine, total alkalinity, calcium hardness, stabiliser or salt.
- Enter your current reading and your target, using the guidance from your test kit, the product label or the equipment maker. The calculator shows the rise needed.
- Choose the product. It fills in a typical strength, so change it to the strength on your label, such as the available chlorine or active ingredient percentage.
- Add the dose in stages to the pool water, as the label directs. Let it circulate, test again and only then add more.
Tips and common mistakes
- Never mix chemicals together, even in a bucket. Add each one separately, to the pool water.
- Always add chemicals to water, never water to chemicals. Follow the label if a product needs dissolving first.
- Check the strength on the label every time you buy. Products with similar names can differ, and some lose strength as they age.
- Wear the protection the label asks for, and store chemicals as directed, away from children and away from other chemicals.
Questions
How much chlorine do I add to my pool?
It depends on your pool volume, how far you need to raise the level and the strength of your product. Enter those in the calculator to get a dose, then add it in stages and retest before adding more. Use your test kit and the product label to set the target.
How do I calculate pool chemical dosage?
Work out the rise you need from your test, then use your pool volume and the product strength to find how much product gives that rise. The calculator does this sum for you. Always check the result against the product label.
What levels should my pool chemicals be at?
Target levels depend on the pool type, surface, sanitiser system and equipment. Use the ranges given by your test kit, the product labels, the equipment maker or a local pool professional. Enter the target you choose in the calculator to work out the dose.
Can I add pool chemicals at the same time?
Do not mix chemicals together or put them in the same bucket. Add each one separately to the pool water and let it circulate before adding the next, following each label. Test again before adding more.
Why is my pool reading still low after adding chemicals?
The pool volume may be larger than you thought, the product may be weaker than expected because of age or storage, or something in the water may be using it up. Recheck your volume and the product strength. Retest after circulation and add more in stages only if needed.
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