Calculate sodium thiosulfate doses for garden water treatment. Estimate chlorine removal needs accurately. Support safer irrigation planning for sensitive plants.
| Use Case | Water Volume | Oxidant Type | Measured Level | Purity | Safety Margin |
|---|---|---|---|---|---|
| Seedling tray rinse | 100 L | Free chlorine | 1.0 mg/L | 99% | 10% |
| Small tank irrigation | 500 L | Free chlorine | 2.0 mg/L | 98% | 10% |
| Greenhouse reservoir | 1000 L | Chloramine | 2.5 mg/L | 99% | 15% |
| Bed flushing water | 2 m3 | Mixed oxidants | 1.8 mg/L | 95% | 12% |
The calculator converts all water volume values into liters first. It then subtracts the target residual from the measured oxidant reading.
Reactive need (mg/L) = Measured reading - Target residual
Pure sodium thiosulfate (mg) = Water volume in liters × Reactive need × Dose factor
Default factors are 7.9 for free chlorine, 10.5 for chloramine, and 9.2 for mixed oxidants. These factors estimate sodium thiosulfate pentahydrate demand.
Product dose (g) = Pure dose ÷ Purity fraction
Final dose (g) = Product dose × (1 + Safety margin)
Stock solution volume (mL) = Final dose ÷ Stock strength fraction
Enter the total volume of irrigation or treatment water. Select the correct volume unit.
Choose the oxidant type that matches your water test. Enter the measured chlorine or chloramine value in mg/L.
Add a target residual if you do not want total removal. Enter product purity from the label and add a small safety margin.
If you plan to dose a liquid stock, enter the stock strength. Press calculate to view the result above the form.
Use the CSV button for records. Use the PDF button for a simple printable report.
Sodium thiosulfate helps neutralize chlorine in water. Many gardeners use municipal water for beds, trays, and tanks. Chlorine can stress roots and beneficial microbes. This calculator gives a practical dose estimate before watering sensitive plants.
Small gardens often store water in drums or tubs. Larger sites may use holding tanks or greenhouse reservoirs. The calculator works for both situations. It converts common volume units and shows a direct product dose in grams and stock solution volume in milliliters.
Overdosing can waste material. Underdosing may leave chlorine behind. This tool balances both risks. It uses oxidant type, residual target, purity, and safety margin. That makes it more useful than a simple one line estimate.
Gardeners often manage seedlings, herbs, ornamentals, and propagation benches. These plant groups can respond differently to treated water. The calculator includes a notes field and plant group field for recordkeeping. Export options also help with repeated mixing tasks.
Water chemistry changes with source, season, and treatment method. Test strips or meter readings improve accuracy. Sodium thiosulfate should be measured carefully and mixed evenly. For valuable crops, confirm results with a fresh water test after treatment.
The page keeps sections stacked in a single column for easy reading. The form uses responsive columns for data entry. After submission, the result appears below the header and above the form. That keeps the main answer visible during repeated adjustments.
It reduces chlorine and related oxidants in treated water. This can make water gentler for roots, microbes, seedlings, and propagation systems.
Yes. Select chloramine in the form. The calculator uses a higher demand factor because chloramine usually needs more sodium thiosulfate than free chlorine.
Not every product is pure active material. Lower purity means you need more total product to reach the same neutralizing effect.
A small margin such as 5% to 15% is common for practical mixing. It helps cover test variation and minor dosing loss.
It is a dosing aid, not a crop guarantee. Sensitive plants, hydroponic systems, and specialty crops should still be checked with a water test.
Enter the percentage of your prepared liquid solution. For example, a 10% stock contains 10 grams of product per 100 milliliters of solution.
No. It estimates sodium thiosulfate demand for oxidant reduction only. It does not correct pH, hardness, salinity, or nutrient imbalance.
Yes. Retesting is the best way to confirm that the target residual was achieved, especially for valuable crops or changing water sources.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.