SH Dilution Chart for Soft Wash Batch Mixing
Choose the source strength and target batch strength, then use the chart to split a 10-unit final batch between sodium hypochlorite (SH) source and water. The units can be US gallons, litres or another single volume unit.
This chart checks batch arithmetic. It does not select a treatment strength for a surface. Follow the product label, SDS, equipment instructions and applicable rules.
10-unit SH dilution chart
| Target batch | 12.5% SH source | Water | 10% SH source | Water |
|---|---|---|---|---|
| 0.5% | 0.4 units | 9.6 units | 0.5 units | 9.5 units |
| 1% | 0.8 units | 9.2 units | 1 unit | 9 units |
| 2% | 1.6 units | 8.4 units | 2 units | 8 units |
| 3% | 2.4 units | 7.6 units | 3 units | 7 units |
| 4% | 3.2 units | 6.8 units | 4 units | 6 units |
| 5% | 4 units | 6 units | 5 units | 5 units |
The table assumes the stated source strength is current and no surfactant is included. If a compatible surfactant is part of the final batch, subtract its volume from the water, not from the SH amount.
SH source volume = final batch volume × target concentration ÷ source concentration.
Water = final batch volume − SH source volume − compatible surfactant volume.
Worked example
For 10 US gal at 2% using 12.5% source, SH volume is 10 × 2 ÷ 12.5 = 1.6 gal. With no surfactant, water is 10 − 1.6 = 8.4 gal.
For a 25 L batch with the same percentages, multiply the chart's 10-unit amounts by 2.5. That gives 4 L of 12.5% SH source and 21 L of water.
Do not confuse batch strength with outlet strength
A dedicated batch pump may deliver roughly the concentration held in its tank, subject to equipment and product behavior. A downstream injector mixes the pickup solution with more water. Its outlet concentration is lower and depends on the measured draw ratio.
Use the SH Dilution Calculator for any batch size. For injector math, use the Downstream Injector Calculator and the downstream ratio chart.
Mathematical estimates only. Never mix sodium hypochlorite with acids, ammonia or incompatible chemicals. Use only label-compatible surfactants and required PPE. Source strength can fall with age, heat and storage conditions.