How to Choose the Right Proportioner for Your Soft Wash Setup

A proportioner is one of the most underrated pieces of equipment in a soft wash rig. Get it right and you'll save chemical, improve results, and have more flexibility on the job. Here's what to look for.

What Does a Proportioner Do?

A proportioner mixes your chemical concentrate with water at a set ratio before it reaches the gun. Instead of pre-mixing a full tank at a fixed dilution, you can dial in the exact ratio you need for each application — stronger for a heavily stained roof, lighter for a vinyl fence.

Why It Matters

Without a proportioner, you're either pre-mixing at one ratio for the whole job or swapping tanks. Both approaches waste chemical and limit your flexibility. A proportioner lets you run one tank of concentrate and adjust on the fly.

Types of Proportioners

Fixed ratio proportioners deliver a set mix ratio — simple, reliable, and low maintenance. Good for contractors who run the same mix on most jobs.

Adjustable proportioners let you dial in the ratio in the field. More flexibility, slightly more complexity. Ideal for contractors who handle a variety of surfaces and applications.

Key Specs to Evaluate

• Flow rate compatibility — make sure the proportioner can handle your pump's GPM output without restricting flow
• Chemical compatibility — it needs to be rated for sodium hypochlorite and surfactants, which are corrosive
• Ratio range — check that the adjustment range covers your typical mix ratios (usually 0.5% to 6% for most soft wash applications)
• Build quality — look for chemical-resistant materials throughout; avoid anything with brass or aluminum components in the chemical path

Installation Tips

Mount the proportioner downstream of the pump and upstream of the hose reel. Keep the chemical inlet line as short as possible to minimize draw issues. Use chemical-resistant fittings throughout and check connections regularly — proportioners see a lot of chemical exposure.

Bottom Line

A quality proportioner pays for itself quickly in chemical savings alone. If you're running a professional soft wash operation without one, it's worth adding to your next equipment order.