SH Tank size

New guy here! Currently building a 4x8 trailer and I am stuck on what size SH tank to go with due to the lack of space. I have a 150G water tank and small reel installed as of today. I’ve built a manifold with metering valves for soap, water, and SH. I’m running a 12v pump 5.5 gpm. Anyways I’ve only got about 3 feet of trailer left for the SH tank. Ive been cleaning homes with 15 gallons of mix at 3% a tad high I know. Anyways I know that 15 gallons mix will do the job. The real question is how much bleach will a manifold system draw? Will my 15 gallon tank be efficient? Or do I need to go up to 55?

In all seriousness, you out grew that trailer before you bought it. I carry as much bleach as possible, two 50 gallon tanks, and fit whatever size water tank is feasible for the left over space. 225 on some trucks, a 65 on one.

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A proportioner will draw from 0% to whatever strength your bleach is.

You need to start off with a bigger trailer, that little thing isn’t gonna last long.

Where’s your machine?

Yeah without a doubt, I’ll make it work for now. Definitely won’t be any wasted space lol

If you’re talking about my truck, It’s a bit embarrassing to see a cummins pulling this tiny trailer haha like to keep it out of view cause it’s not pertinent. I could add a second level to this trailer if need be but I’d like to see if I’m really gonna need more than 15-25 gallon tank before I do all that. Today was just about getting the tanks situated. Then plumbing and so on so forth.

Well, I do mostly housewashes and carry a vertical 55 gallon SH tank. The most I’ve ever used in 4 years is 20 gallons in one day, mostly downstreaming with occasional 12v use. My buffer is also 55gal vert tank, and this is using an 8gpm machine.

As you’re strictly using a 12v for now you’ll definitely want to back off that 3%, WAY too hot for a housewash. You’re gonna kill a lot of plants doing that, not to mention etching windows. 1% is the gold standard, maybe 2% for stubborn gutters.

May I suggest you do a LOT of reading on here before continuing this venture?


I’ve done my due diligence still learning though. I’ve washed 8 homes so far. Have kept in touch with customers no plants killed and no noticeable change to the windows or the siding of said homes besides it being clean. This isn’t a full time gig, at max I do 2 homes a week that’s why I feel I won’t be needing all the bleach listed in above statements.


Affirmative ! It’s impressive how cheap it is for the coverage you can obtain. Anyways man I just wanted to know what size tanks would be sufficient. I want efficiency but that will come with experience and expansion. Been hard to locate 55g drums so I figured smaller tank if it will work may be easier for now. Just gonna do a draw test and figure it out. Appreciate the help. And no I won’t be applying 3% mix with my new setup. I think you missed that in my main post.

I think you’re fine with what you have as a purely softwash setup, just know you’ll want an actual machine at some point so you can start downstreaming.

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At 2 house washes a week I wouldn’t even worry about a tank. Take a couple of 5 gallon jugs of SH and downstream. 12v pumps have their uses but I wouldn’t dedicated a whole trailer to one.


It’s how a fair amount of contractors wash houses over here, just using a 12v.

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I have a 65 gallon on my harbor freight 4x8 trailer with a 26 gallon sh tank. Unless you are rolling an 8 gpm on that there is no need for 125 gallon tank. I use a 5.5 belt drive and have never come close to running out of water.

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I agree 100% tank is overkill but got it on a good deal. This is my first trailer build so I’m learning something new every time I add to it.

So I had a job where I tried downstreaming did not go well. I’m assuming a stock injector on a 300 dollar lowes pressure washer was the issue. Downstreaming seems to be the easiest option but I didn’t enjoy my experience with it

You just have to be patient with it, longer dwell times with a weaker mix but everything’s out of one hose. You’ll make up the time not fighting and untangling hose. They both work, downstreaming is just more straight forward and less mucking around. 90% of my homes are downstreamed. Give it another chance.

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Um, yup…there’s your problem.

A 5.5 or 8gpm will blow your socks off how fast it’ll wash a house.

You’ve read 41 minutes, keep going…you’ll have a eureka moment and everything will click into place.

Just a piece if strong advice from someone that started four years ago, I sorely wish I had bought a belt drive right off the bat, for many reasons.

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I have a 4x7 trailer with a 16 gallon SH tank + surfactant. No complaints. I also have a 5.5 gpm 12v rig that comes in handy on special occasions but I would much rather downstream siding with the direct drive 4gpm (skip the EIFS, that stuff is cursed). The gear drive pump has been delivered & things are about to speed up a bit.

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What problems have you had with EIFs? It should be easy work…not like vinyl easy, but still stucco-like.

I believe u can carry a max of 120gl before hazmat permits kick in.
In theory, or actuality, if you have a drop of SH on ur buffer tank it all of it is considered chem.