The M6 Injector is a popular adjustable nozzle for downstream chemical injection in soft washing and pressure washing applications.
It allows chemicals (like sodium hypochlorite, or SH) to be drawn and mixed externally after the pump, with variable spray patterns from 5° to 60°. Draw ratios (expressed as water: chemical) depend on your pressure washer’s GPM flow rate and whether a proportioner is used. All ratios below are approximate, based on manufacturer charts and can vary slightly by equipment setup, pressure, and elevation.
Maximum Draw Ratios (No Proportioner, Fully Open) This achieves the highest chemical draw (lowest water: chemical ratio). No colored proportioner is inserted into the chemical barb.
- 2 GPM: 0.8:1
- 3 GPM: 1.2:1
- 4 GPM: 1.6:1
- 5 GPM: 2:1
- 6 GPM: 2.4:1
- 8 GPM: 3:1
Ratios Using Main Proportioner Colours. The M6 comes with 4 colour-coded proportioners that restrict flow to achieve higher dilution ratios. The “main” ones commonly used for soft washing (especially with SH mixes) are beige and red, as they typically yield 1-2% SH in the output when starting with 12.5% SH input. Other colours are available for finer control or different chemicals/applications. Insert the proportioner into the chemical barb to set the ratio.
Beige (common for standard house washes with SH):
- 2 GPM: 6:1
- 3 GPM: 8:1
- 4 GPM: 10:1
- 5 GPM: 13:1
- 6 GPM: 16:1
- 8 GPM: 20:1
Red (for slightly stronger SH mixes or adjustments):
- 2 GPM: 9:1
- 3 GPM: 12:1
- 4 GPM: 16:1
- 5 GPM: 20:1
- 6 GPM: 24:1
- 8 GPM: 28:1
Maximum Draw Expressed in % of SH Draw The “% of SH draw” refers to the percentage of the output flow that consists of drawn SH (the chemical draw rate). For a given water: chemical ratio (R:1), this is calculated as [1 / (R + 1)] × 100%. This assumes an undiluted input chemical; it represents how much of the sprayed mix is pulled from your SH tank vs. water from the pressure washer.
Using maximum draw (open, no proportioner):
- 2 GPM (0.8:1 ratio): ~55.6% SH draw
- 3 GPM (1.2:1 ratio): ~45.5% SH draw
- 4 GPM (1.6:1 ratio): ~38.5% SH draw
- 5 GPM (2:1 ratio): ~33.3% SH draw
- 6 GPM (2.4:1 ratio): ~29.4% SH draw
- 8 GPM (3:1 ratio): ~25% SH draw
If your input is 12.5% SH, the actual SH concentration in the output would be this draw percentage multiplied by 12.5% (e.g., at 4 GPM: 38.5% × 12.5% ≈ 4.8% SH applied). For precise mixing, test with your setup, as real-world factors like hose length and viscosity affect results.
Key Differences Between M6 and SoftWash Proportioner
Mixing Method and Precision:
- M6 uses passive Venturi draw (post-pump), leading to variable ratios influenced by GPM/pressure; SoftWash proportioners actively meter flows (pre-pump) with scaled valves for exact, repeatable control and less waste.
- Ratio Handling: M6 ratios are tip-dependent and indirect (swap colours for changes); SoftWash ratios are dial-set and direct, allowing multi-component blends (SH + surfactant) without recalibration.
- Percentage Capabilities: M6 maxes at ~4.8% SH due to injection limits, suitable for lighter jobs; SoftWash can hit 6-12.5% SH for tougher cleaning, with finer % adjustments (e.g., 0.5% increments via charts).
- Equipment and Application: M6 integrates with existing pressure washers for hybrid use (high/low pressure); full SoftWash is standalone, low-pressure only, with tanks for batch-like consistency but on-demand mixing—ideal for roofs/siding but more investment.
In summary, M6 offers simplicity for downstreaming but trades off precision and strength, while SoftWash proportioners provide professional-grade control for consistent, high-potency mixes. Choose based on job scale: M6 for starters, SoftWash for dedicated operations.
Last updated: June 11 2026