X-Jet vs downstream injector for soft washing

Both tools do the same job: they use a venturi to pull chemical out of a bucket and into the water, so the mix never goes through the pump. Where that venturi sits is what changes the strength, the reach and how much of your kit gets wet with bleach.

Draws are written chemical first, as on this site’s calculators: 1:10 is one part chemical to ten parts water. X-Jet figures are the maker’s own, read 18 October 2026.

A small venturi fitting plumbed between the pump outlet and the high-pressure hose, with a tube running to a bucket. It only pulls chemical when the pressure after it drops, and the thing that drops it is the black soap tip (~65 deg), the widest and lowest-pressure tip in the set. Swap to a rinse tip and the draw stops. That is how you go from soap to rinse without touching the bucket.

The draw runs about 1:8 to 1:20 depending on the injector, hose length and nozzle. A 1:10 draw with 12.5% stock puts roughly 1.1% SH on the wall, which is the middle of the 0.5-1.5% siding band this site publishes. For a one- or two-storey house wash that is the right strength already, and it is why the injector is how most operators start, as the soft washing guide explains.

The trade-off is where the mix travels. Everything after the injector carries it: the hose, the reel, the gun and the wand. Run clean water through the line before you pack up, and expect the gun’s seals to see bleach every working day.

Downstream injector bypass

An injector is a narrowing in the high-pressure line, and it stays there when you go back to pressure washing a driveway. A bypass loop takes it out of the way. Distributors sell it as a kit: two tees, a short high-pressure whip hose and a ball valve, plumbed so the water can run around the injector. Valve closed, water goes through the injector and you can soap. Valve open, most of the flow skips it, which is what you want behind a surface cleaner.

Where it falls short: strength and height. The draw caps the wall strength, and the soap tip throws a short, wide fan. Long-reach downstream nozzles exist that still drop the pressure enough to draw (the X-Jet’s maker sells one it rates to 60 ft), but the strength ceiling stays where the draw puts it.

The X-Jet, made by X-Jet Technologies, puts the venturi inside the nozzle. Water at full machine pressure passes a precision orifice in the nozzle body, and the low pressure it creates pulls chemical up a separate 15 ft suction hose from a pail. The mixing happens at the tip, so the maker’s spec sheet can say that no chemical runs through the pump, hose, reels, gun, lance or quick connects. It clicks onto the gun or lance on a 1/4 in quick connect.

The kit adds an inline shutoff valve on the suction hose, which is the soap-to-rinse switch: close it and you are rinsing with the same nozzle. Strength is set by 14 colour-coded proportioner tips pushed into the chemical hose barb. There are two bodies. The Original has a fixed zero-degree stream plus a screw-on close-range nozzle, and the maker says it reaches 3 to 5 ft higher. The M5 has a twist collar that runs from a straight stream to a 60-degree fan.

From the maker’s M5 spec sheet and product page, read 18 October 2026. Reach is measured from the ground and rises with flow; the maker’s headline “up to 40 ft or more” is a 4 GPM-and-up figure.

Size it to the machine you actually have. The maker warns that an orifice much bigger than your machine’s flow will not draw chemical at all, especially on smaller machines, so measure your real GPM rather than trusting the sticker. The nozzle size calculator works from the same PSI and GPM.

Where it falls short: one more hose to drag, an orifice to change when you change machines, ratios that shift with your GPM, and a small machine gives up most of the reach. Below 4 GPM the maker’s own figure is 15-20 ft.

This is the difference that decides most purchases. A downstream injector dilutes your bucket about tenfold, and nothing you do at the bucket gets you past that: hypochlorite is sold at 12.5%, so the wall strength tops out around 1.4% even on a strong draw. The X-Jet draws far harder, and its colour-coded proportioner tips let you choose how much harder.

From a 12.5% bucket. X-Jet rows are the maker’s own proportioner chart at 4 GPM, which it calls approximate; the maker writes them water first (5:1), this site writes chemical first (1:5), and both mean one part chemical to five of water. Downstream rows use this site’s working draw of 1:8 to 1:20. Work your own numbers in the downstream injector calculator.

Two things in that chart catch people out. First, an X-Jet tip’s ratio moves with the machine: per the maker’s chart the black tip draws about 1:3 on a 2 GPM machine and about 1:11 on an 8 GPM one, so a tip that is right on your machine is wrong on a friend’s. Second, the X-Jet’s tip colours are its own code. A black proportioner has nothing to do with the black soap nozzle on the nozzle chart.

A downstream injector cannot reach roof strength at all. The working figure is ~3% SH at the shingle, and from 12.5% stock that needs about one part to three of water; a draw of 1:8 or weaker never gets there. The X-Jet can reach it, which is exactly why the question comes up.

For house washes at siding strength on walls you can reach, the downstream injector does the job and costs least. Buy the X-Jet when the walls get taller, when you want a stronger mix than a draw of about 1:8 allows, or when you are tired of bleach in the gun. Nothing stops you keeping both: the injector for low walls, the X-Jet for the gable ends.

Whichever you choose, the bucket is still arithmetic. The sodium hypochlorite guide covers why the drum is weaker than its label by August, and pressure washing chemicals covers the surfactant that goes in with it.