Surface cleaning nozzle size

Running the 20in Northstar surface cleaner. Wanting to change out the supplied 25⁰ tips for 40⁰. Thinking it will still be plenty of cleaning power and reduce chances of etching. Is that correct?

5gpm 3000psi machine

No. The degree of the nozzle doesn’t change the PSI, the orifice size does. Lots of info on here about surface cleaner nozzles just use the search bar above.

Thanks. Figured orfice size was key.

I would buy a gauge, then buy 25030 and 25035 tips. I prefer 2500 PSI or less.


From one newbie to another I’ll share my post from the other week about this.

Nozzle Information

@Jake_Lambert shared this helpful link with me. Simplifies the whole matter. The key that I had to wrap my mind around was to remember to divide your GPM by how many nozzles your surface cleaner has.


I’m thinking of getting nozzles to reduce pressure to like 1000 or 1200 for sensitive areas. I love my size 20 tip on the wand it has just enough punch to clean most things without risk of damage. Have you ever used really big tips like that on a surface cleaner?

No not yet

My 25025’s on a 4 nozzle bar give me right at 2000 psi after 250 ft of hose. Thinking about going to 2502 to see if I can get it to that 2500 range we all talk about. But honestly the 2000 has been working great.

I have tips that give me 700
Psi. They are on my 2 nozzle bar. Just haven’t used it yet.

You will never use it. 700 psi out of surface cleaner doesn’t do anything, your rinsing at that point.

I run the same and see 2300PSI at 200ft of hose.

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Tell that to the roof shampoo folks

I’m looking to get tips for 1000-1200 psi to gently clean newer cream top concrete (at least 1 year old). I had a bad experience with a cream top driveway that was actually two years old but the contractors did a terrible job and even using 1000 psi out of the wand caused issues. I’m nervous about cleaning concrete that looks new even if it’s a-year-old using the surface cleaner. But what I really want is to order the brown stuff and do a 1-2 punch with the sh like @Firefighter4hire does but the place that sells it doesn’t ship to California. I looked at the post that involved @CaCO3Girl and she explained a bit of what is in the brown stuff (sodium hydroxide) but there is other things in it too and I can’t find anything else like it where I can buy online and have it shipped to me. Until I can find a similar product I really don’t even want to do anything with newer concrete.

I’ve switched out of the lab and into a regulatory position. California has made it VERY difficult to sell cleaning chemicals into. Your best bet is to go to a HVAC professional store. Cc Dickson, Johnstone supply, national refrigerants are a few I can think of. The very potent brown stuff is sold there under several names. You aren’t going to find it at Walmart or Home Depot. The industrial chemicals are easier to sell into California than the general consumer chemicals.


I have one of these stores in my city. This information is gold! Do you know what I should ask them for to try and get a comparable product when I get there? The only thing I really know is it has sodium hydroxide in it but not really sure what else… thank you!

Brown stuff is fairly universal…in HVAC land I know one is called Foam N Clean by Atlantic Chemical (Ace), Nu Calgon sells one as well. They all have high levels of sodium hydroxide, a bit of potash, and lots of rinsing agents.

I can’t say how it will work on your project, I’m not a field person, but the chemistries are similar in all of them. It’s Sprite vs 7-up, very close but slightly different. Try out a few, or buy the one on sale. Check the dilution rates to make sure you are comparing apples to apples. And please know that this stuff eats aluminum even when cut in half with water. This isn’t something to mess around with, please be careful.

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Invite them to the forum and I’ll tell them.

@CaCO3Girl I pay special attention to your posts, your knowledge blows me away, thank you.

Awww thank you. I’m only here when someone @CaCO3Girl me to be here since I am no longer making the chemicals in the lab. I made a career change to regulatory and compliance. Now I spend my days arguing with retailers and making sure our labels say the right things, and DON’T say the incorrect things. I also write SDS’s.

I have no actual pressure washing experience but the chemicals, I have tons of experience there. I feel a bit like the magician behind the curtain sometimes, lol! Chemicals are the unknown to a lot of folks, I’m happy to share my knowledge.


I found a product called Hotsy Brown. It has 2% sodium hydroxide and is listed as a degreaser. It also says not to use on aluminum so I’m thinking this may be a good alternative? Here is the sds sheet:
Does this look like it could be the same thing?