Sodium hypochlorite is widely used for disinfection and oxidation. The dosing calculation is simple, but the required chlorine residual or demand is process-specific and should be established through the treatment objective and water quality.
Step 1: active chlorine requirement
For a target of 2 mg/L at 200 m³/hr:
Active requirement = 200 × 2 ÷ 1000 = 0.40 kg/hr.
Step 2: correct for product strength
If the product is treated as 12.5% available chlorine by weight for the calculation:
Product = 0.40 ÷ 0.125 = 3.20 kg/hr.
Step 3: convert to volume
If density is 1.20 kg/L, volume = 3.20 ÷ 1.20 = 2.67 L/hr.
Important practical factors
Hypochlorite strength decreases during storage, especially with heat, time and contamination. Use current product data and manage storage accordingly. The actual dose needed to achieve a residual depends on chlorine demand, pH, contact time and water composition.
Compatibility and safety
Keep hypochlorite away from acids and incompatible materials. Acid contact can release chlorine gas. Follow the SDS, site storage segregation and dosing-system material recommendations.
Use the Ramven Sodium Hypochlorite Dosing Calculator to convert a validated dose into kg/hr and L/hr.