# Downstream ratio

Hey guys, rookie question again, how do I calculate how much sh % is getting on the house. I have a 20 to 1 injector, 4 gpm pw, using 6% bleach. If someone could give me a formula on how to calculate it I would appreciate it. I’m using straight sh right now, no added water. Seems to be working really good just want to make sure it’s not to much . Thanks

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You have achieved nirvana when it seems to be working good. As long as it takes a few minutes to begin to see results, you’re not too hot. Ratio numbers, percentages and the like are nice but what happens when you wash in the shade vs. the sun? Do you need a different ratio then? What happens when you get two month old bleach vs. two week old? What happens when the outside temperature drops twenty degrees? All of these things affect your cleaning as well as the effective percentage on the wall.

It’s nice to know numbers, it’s better to know how to wash. And it seems like you are getting there.

Start with a five gallon container full of water hook your down-streamer to it and add the amount of pressure hose that you usually use. Start your pressure washer and spray your gun into a fifty five gallon container. When it has fifty gallons in it, stop. Measure how much has been drawn from your five gallon bucket. Let’s assume three gallons. So you have 47 gallons of pressure wash water and 3 gallons of soap. Let’s call that 47/3. That equals 15.6 to 1. If you are using 6% bleach, divide 6 into 15.6. Answer? .3846. You are getting .38 percent bleach on the wall. Now what? You should get nervous because everybody knows that .38% bleach on the wall will never work. But you just told me that it did.

Holler back.

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Wow that’s alot to think about Tim, so my next question is if I was using a 10/1 injector would that put me at .6 then. Assuming everything else stays the same, thanks for answering my questions Tim, and by the way I did my first deck today and it turned out great. Tried to post pictures but it won’t let me, says I don’t have enough data or something

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In theory, yes.

Lets say I adjust my injector, where I’m putting out 20 gallons of water and 3 gallons of sh. If my calculations are right that’s about .9 hitting the house, given like you said the factors would greatly influence this, just checking my math.

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Or Mix 2 gallons SH with 3 gallons water in a 5 gallon pail and was away :0)

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I’m using a five gallon bucket but only sh I can get my hands on is 6%, I was just trying to see if my mix is strong enough

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Play with it. Make it 3 sh and 2 water

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Dont over think it too much Matt. Once you get your mixture down just stick with it. No need to over/under adjust unless you’re dealing with less mold than dirt and grime etc. Try to get your hands on 12.5% SH if you can. It will save you a ton of money in the long run and works much quicker for you. Just make sure you pre-soak and post rinse everything afterward. Purchase so ELEMONATOR from Pressuretek.com. Its not only stable for bleach is also boosts the akaline in the bleach not to mention a nice lemony clean scent. Good luck buddy!

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Dont over think it too much Matt. Once you get your mixture down just stick with it. No need to over/under adjust unless you’re dealing with less mold than dirt and grime etc. Try to get your hands on 12.5% SH if you can. It will save you a ton of money in the long run and works much quicker for you. Just make sure you pre-soak and post rinse everything afterward. Purchase so ELEMONATOR from Pressuretek.com. Its not only stable for bleach is also boosts the alkaline in the bleach not to mention a nice lemony clean scent. Good luck buddy!

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I’m a newbie! What does SH stand for?
I have not started working yet. Plan to get going in spring of 2015.
And if I plan to do houses and concrete what GPM/Pressure machine should I buy?

Ronnie
ProAqua-Clean L.L.C.

SH is sodium hypochlorite (aka chlorine). Equipment depends heavily on your business plan. What will you be targeting? Residential/ commercial, exhaust cleaning, fleet washing, etc… What you begin with will not be the equipment you end up with. Your usage and technique will evolve and dictate your needs. My advice to you is to figure out what you’re going to wash, what you’re going to spend, and then call a reputable supplier like PressureTek and they can help you from there. A good vendor can go a long way to providing you with the right equipment to meet your needs.
Our goals are common but our methods, equipment, and preferences vary. I wish there was a much simpler answer

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I would also recommend going to the 2014 Pressure Washing Convention in Nashville in August. The amount of time, money, and wasted effort you will save by attending and taking classes will pay for itself for ten years.

I wish there was something like it available when I started. I cringe when I remember all the mistakes and missteps.

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I’m trying to get off work. I still work for the Man! I will be calling you to talk about a membership and the Convention.

Ronnie
pac2015
ProAqua-Clean L.L.C.

Sure thing.
Gimme a call, text, or email whenever.

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Hello Tim. I’ve read around and have seen several comments about checking the ratio, and I’ve seen percentages. What I don’t recall seeing is a target. What percentage is considered good? In your above example you comment that .38% will never work. Using the same figures in your example, if I changed from 6% bleach to 12.5% then that number increases to .80%. I would assume that is a good number, but I don’t honestly know that for sure. So where should we land when checking our ratio?

Also, are you measuring the % of the mix onto the house? Wouldn’t those numbers change based on how much bleach is in your 5 gallon bucket? Our typical mix is 50/50 water/bleach using 12.5%.

.08-1% target will put you in the ballpark. You may need to adjust depending on your needs. Too weak of a mix means more time on site, too strong of a mix will clean faster at the risk of hurting vegetation and sometimes painted surfaces.

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Sandi here is what works for me. I run a 4gpm machine.my bucket test showed a 20 to 1 injection ratio. My 5 gallon
bucket contains 3 gallons 12.5 % sodium hypoclorite, 2 gallons water and 5 ounces of bob’s elemonator. The only time
this has not worked for me is if my 12.5% bleach was out dated junk! If you are running a higher gpm machine you will
have a higher dilution ratio. Just sharing what works for me at 4 gpm. Hope this helps:)

Bill Sullivan
Bill’s Window Cleaning.
902-471-8008.

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I am with JC. Looking for 3/4 of 1%.

But we don’t spend a lot of time analyzing it.

We run 12.5% with 5 ounces of eLemonator because our downstream ratios are pretty sad at 8 and 10 gpm.

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Thanks for the replies! So looks like we’re ok, but on the cooler side of the mix. We have bumped it up to 3 gallons SH and 2 Water with 5 oz of elemonator. Recently did a dryvit home and we downstreamed straight SH with 5 oz of elemonator. BTW, our setup is also 4gpm cold.

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