If use 8.25% and increase the mix to 50/50 or 60/40 with water.Can I get the same result as 12.5% SH ?
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It’s a numbers game.
What would your ratio be if you had 12.5%?
Good, now do the math to see what percentage SH is hitting the roof.
Okay, now, how much water would you have to mix with a gallon of 8.25% to get the same concentration on the shingle?
It really is that simple.
Holler back if you need help with the equation.
I can do the mat 
The calculation is the last thing I worry about ,
Just wanna make sure I can get the same result with 8.25% bleach .
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It’s not what you start with.
It’s what you finish with.
You may just have to try it and see how it goes. Bottled bleach weakens as it sits on the shelf. Mix a small amount and do a test first. Adjust your mix as needed.
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What percent do you want hitting the shingle, [MENTION=444]Tim[/MENTION]?
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We put 20 gallons of bleach to 30 gallons of water and then a big old fat healthy dose of Roof Snot.
If we have 12.5% bleach then I reckon our percentage on the shingle would be 40% of 12.5%
We buy bleach off the shelf that may not necessarily be as hot as we would like.
Better bleach means less percentage is needed.
So you are hitting the shingle with roughly 5% SH?
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I never thought of it that way, but yes, I suppose that’s true.
Ratios and percentages is relatively new math to me. In my machining and fabrication background, fractions and decimals are king. I have got to get this firm of weights and measures nailed down! That’s why I was asking. I hate feeling like I’m just “winging it”
DS injection ratios added into the mix really throws me off too! How do you figure the ratio on your injector? (No, I’m not DSing roof mix) I’m just trying to nail this math down
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[MENTION=8115]AquaTek2013[/MENTION] Good question, I too will be watching this one!
You won’t get upset with me if I told you to do a search will you?
Good, I’ll help you with it.
Do a google search
site colon pressurewashingresource.com downstream ratio
Read
Lol! You can’t upset me!
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You can find out exactly how much your downstreamer is pulling my timing how long it takes you to fill up a 5 gallon bucket from your machine. Then time how long it takes you to suck it out using the downstreamer.
Wouldnt the easier method be to fill a bucket with a known volume of water, say 1 gallon. Then downstream into another container. When downstream bucket is empty, turn off machine and measuer the collected volume. If there are say 11 gallons in the catch, you know you have 10:1 ratio (as 1 gallon was from the downstream bucket, and 10 gallons of added water). Make sense?
Makes sense. Only a full decade too late, Troy.
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Just came to the forum. Didnt take note of the thread post date. 
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Don’t sweat it, you’re not the first to do that. However, I think you now hold the record for oldest thread revival.
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