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Chlorine Dose Calculator for Tanks and Water
- Grams = litres × mg/L ÷ (10 × strength %)
- Strength is on the label
- Use products approved for drinking water
- Test free chlorine after contact time
Chlorine Dose Calculator
Example figures only: replace them with your own. Results update as you type.
Liquid chlorine strengths vary; for a liquid, grams ≈ millilitres is an approximation. The product label and your water engineer take priority.
Which Dose?
Routine disinfection uses a low dose so a small free chlorine residual remains (WHO guidance: at least 0.2 mg/L at delivery, below 5 mg/L). Shock disinfection of a new or contaminated tank uses a much higher dose for a set contact time, then the tank is flushed. See how to chlorinate a tank or borehole.
Automatic Dosing
| Product | Price |
|---|---|
| Dosing Pump 2l/h | KSh 23,000 |
| Dosing Pump 5l/h | KSh 28,000 |
| Chemical dosing tank | KSh 12,000 |
Current listed prices incl. VAT (updated 4 October 2026).
Safety
- Never mix chlorine products or chlorine with acids.
- Add chlorine to water, not water to chlorine; wear gloves and eye protection.
Watch: Fabrication and components
Frequently asked questions
How much chlorine do I add to a 1,000 litre tank?
For 2 mg/L with a 65% product, about 3 grams; use the calculator for your product and dose.
How do I calculate chlorine dosage?
Litres × target mg/L ÷ (10 × product strength %) gives grams of product.
What is a safe chlorine level in drinking water?
WHO guidance: at least 0.2 mg/L free chlorine at delivery and below 5 mg/L.
How much bleach do I put in a water tank?
Enter the bleach strength from its label (household bleach is usually a few percent) as the product strength; the result in grams is about the same in millilitres. Use bleach without added scent or detergents only if its label allows water disinfection.
How long after chlorinating can I drink the water?
After the contact time on the label; flush shock-chlorinated tanks before drinking.