Running SH through pressure washer

I recently purchased my new pressure washer. 2700 psi and 3 gpm! It came with a chemical injector, I have a 5 gallon bucket, 10% SH, elemonator, and a Jrod. I’m curious to know if it’s safe to run SH through the chemical injector. Only asking since I’ve heard a lot of people saying to not run bleach or SH through your pressure washer! I attached a few pictures

You’re good to go.

Just use your DS chemical injector line that’s laying on the floor and you’re fine.

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Great thank you, I was a bit hesitant using it yesterday to clean my patio! It would of saved me a lot of time since I used my pump up sprayer.

You’ll be able to pull a strong mix with that smaller machine.
So you can dilute your SH though if you’re buying it by the gallon and it’s been sitting on a shelf, it won’t be 10% anymore.

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That’s good to know, thanks for the tip. Since you said it could be diluted and not 10%. What would be a good mix ratio for a 5 gallon bucket?

Many guys go 50/50 with smaller units.
But it depends on SH strength and the ratio of what your chem injector pulls.

Also depends on what you’re cleaning.

I understand, my ds injector is a 2.1, 3-5gpm. I’m not sure what ratio it would be. I’ll go over the manual and figure it

You need to do a bucket test.
Using the new DS injector means the manual won’t be of much help.

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On a side note, until you run that black hose back to a buffer tank you’ll have to trigger the gun at least every minute to keep the pump from overheating. I’m surprised that unit came with a plumbed unloader.

I figured, I did a bit of research and I’ll do that soon! Thank you for all your help!

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Let us know what your ratio is. With that small of a machine, it should be a pretty small ratio. I’m guessing easily 10:1 but maybe more like 7:1 or 6:1

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I don’t have a buffer tank… tbh I’m a bit confused on what you said, still a newbie here haha!

Is this just for home use or business? If home don’t worry about a buffer tank. Just be sure you squeeze the gun every minute or so to keep the pump from overheating. Don’t leave it running and go eat lunch.


I have a full time job, I do it as a side gig generally 1-2 jobs a week. I enjoy it and Im really into learning more! Thanks for the tips!

I’ll give some extra clarification since you’re new, and other newbies might read your post and need clarification.

You should not run SH ‘through’ your machine. In other words, you should NOT have a supply tank or SH injector BEFORE the pump. There’s just lots of parts inside the machine that don’t do well with SH and it will increase the likelihood of pump failure.

The alternative is to run the SH ‘after’ your machine, instead of through it. That little “T-shaped doohickey with the clear-ish hose” that you’ve connected after your pump is a Hi-draw Downstream Injector, and is the perfect way to add chemicals to your mix.

At lower PSI and flow, the injector will inject 1 part of whatever is in the bucket it is connected to, into about 5-10 parts of water flowing through your pump. As mentioned above, you can do an injector test to see how much your injector is drawing.

Scenario 1: For a housewash where you are trying to get 0.75% SH on the house, and an injector with a 10:1 ratio, your injector supply bucket would need 7.5% SH. To achieve this you’d mix the 12.5% SH with water in your bucket to get you to 7.5%. (ie, 1.25 gallon SH mixed with 1 gallon of water, and a splash of Elemonator (1 oz).) Many pros don’t do all that fancy measuring, and use a more diluted mix, see if it turns organic material brown within 5 min. If yes, continue using. If no, increase the mix strength by adding more SH to your downstream supply bucket.

Scenario 2: for post treating a driveway you surface clean, you may want to put down a strong 3% mix on the concrete. With a 10:1 ratio, your injector supply bucket should be around 30% SH. Aw, drats! You can’t buy it that concentrated. So your injector won’t work. With a 10:1 ratio, with your downstream supply bucket as pure SH (storebought at 12.5%), the max you can downstream is 1.25%. Luckily, that’ll do for a post-treat. Just not as effective as a stronger mix which would take a 12v system or X-jet.

Hot Tip #1: to keep the injector intake at the bottom of your supply bucket put some weight on it, or route it through a section of PVC pipe so that it stays straight in the bucket.

Hot tip #2: Once you are done using the downstream injector, put the intake in a bucket of clean water to rinse out the inside, which will make it last longer.

Hot tip #3: Buy a spare injector… that one will break in the middle of your most important job. (You don’t have to buy the whole kit. Just the brass injector part.)

Hot tip #4: the injector reduces flow. When you aren’t actively using it, remove it from your setup to maximize flow.

Good luck and welcome to PWR!


All good stuff, except no need to have off injector and rinse. Water flowing thru it does that for you.

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Great stuff! I really appreciate all of your knowledge! I’ll for sure take everything into consideration.

Also, for Scenario #2 I have not been able to get any 12% SH I only find 10% SH. Since my machine is smaller would I be able to get a good percentage with 10%? I didn’t have enough time to do my injector test today so I yet cant say what I’ll be pulling.

Thank you. I understand I can keep my ds injector connected to let water flow through it and that also help clean it. Should I remove my ds injector once I’m done using it too stop the reducing of flow? Or having my ds injector not affect the flow

With 10% SHand somewhere between a 7:1 and 10:1 ratio, you’d be getting 0.7% to 1% at the gun if you have your injector pulling straight SH.

That will work for a house wash, and give you a weak post-treat for concrete.

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