Pool Dose Converter
Formula Used
Chlorine drop equals current free chlorine minus target free chlorine. If the answer is zero or negative, no neutralizer dose is calculated.
Product ounces = dose rate × pool gallons ÷ 10,000 × planned ppm drop × treatment percentage ÷ product strength.
Grams = ounces × 28.349523125. Pounds = ounces ÷ 16. Kilograms = grams ÷ 1000. Scoop count = grams ÷ grams per scoop.
Example Data Table
| Pool Size | Current ppm | Target ppm | Drop ppm | Default Dose | Approx Grams |
|---|---|---|---|---|---|
| 15,000 gal | 8 | 3 | 5 | 15.00 oz | 425.24 g |
| 40,000 L | 7 | 3 | 4 | 8.45 oz | 239.51 g |
| 75 m³ | 5 | 3 | 2 | 7.93 oz | 224.67 g |
How To Use This Calculator
- Test free chlorine with a reliable kit.
- Enter your pool volume and choose the matching unit.
- Enter current chlorine and your desired target level.
- Adjust product strength from the product label.
- Change the dose rate only when your label says so.
- Use staged reduction for safer control.
- Press Calculate and review the result below the header.
- Download CSV or PDF for records.
Sodium Thiosulfate Pool Calculator Guide
What This Pool Converter Does
A sodium thiosulfate pool calculator helps estimate a neutralizer dose before treatment. It converts pool volume, chlorine drop, product purity, and dose strength into practical weights. The tool is useful after over chlorination, shock treatment, or accidental dosing. It does not replace a product label. It also does not replace local pool rules.
Why Careful Dosing Matters
Sodium thiosulfate can lower free chlorine quickly. That makes it helpful when chlorine is too high for swimming. Yet too much neutralizer can remove more chlorine than planned. A pool may then need new sanitizer. This cycle wastes chemicals and may create unsafe water. A staged dose is usually easier to control.
Important Inputs
Start with an accurate pool volume. Gallons, liters, and cubic meters are accepted. Then enter the current free chlorine reading. Use a fresh test result. Enter the target chlorine level next. The calculator only treats the difference between those two values. Product strength is also important. Some granular products are pure. Others include fillers or blended ingredients.
How Results Should Be Used
Read the calculated weight as an estimate. Add chemical only when the pump is running. Broadcast the product slowly near return flow, unless the label says otherwise. Keep swimmers out during treatment. Wait for circulation. Then test chlorine again before using the pool. If the level remains high, repeat with a smaller staged amount.
Practical Pool Notes
High pH, sunlight, stabilizer level, and testing error can affect decisions. Chlorine should never be adjusted from an old strip reading. Use a reliable kit when possible. Avoid mixing pool chemicals in a bucket unless directions clearly allow it. Store sodium thiosulfate dry and sealed. Keep it away from children, pets, acids, and oxidizers.
Best Workflow
Measure first. Calculate second. Dose third. Retest fourth. This simple order prevents most mistakes. When in doubt, use less than the calculated amount. You can always add more after another test. The calculator includes a treatment percentage field for that reason. It also shows ounces, pounds, grams, kilograms, and optional scoop counts. Those conversions make label checks easier.
Record each treatment in a log. Notes help reveal feeder problems or wrong volume assumptions later. Good records improve later dosing.
FAQs
What does this calculator estimate?
It estimates the sodium thiosulfate product weight needed to lower free chlorine by a chosen ppm amount in a known pool volume.
Can I use liters instead of gallons?
Yes. Select liters or cubic meters. The calculator converts the volume to gallons internally, then completes the dose calculation.
Why is product strength included?
Some products are not fully active ingredient. A lower strength means more total product is needed for the same chlorine reduction.
What is the default dose rate?
The default is two ounces per 10,000 gallons for each one ppm drop. You should change it when your product label gives different directions.
Why use a staged reduction?
Staged reduction helps avoid removing too much chlorine at once. It is safer to dose less, circulate, retest, and repeat if needed.
Can this replace testing?
No. Always test before and after treatment. Pool volume errors, product variation, and water conditions can change the real result.
Why did the calculator show zero dose?
It shows zero when the target chlorine is equal to or higher than the current chlorine. No reduction is needed in that case.
Should swimmers enter right after treatment?
No. Keep swimmers out during treatment. Circulate the water, retest chlorine, and follow the product label before allowing swimming.