I tested my draw rate


Tested my draw rate 5 gallons in a minutes so this is my math in that same minute my injector pulled 32oz so my math is this 640oz divided by 32oz so my draw rate is 20:1 did I do this correctly


16 or 32?


What machine specs? Injector size?


If I understand correctly:

  • 5 gallons total sprayed
  • 16oz pulled (one pint, or two cups, just clarifying here that you got that measurement right…?)

You have 640 oz total. To calculate the ratio, you first subtract 16 from 640 to get the total water sprayed in one minute: 624
Then divide 624 by 16. Your ratio is 39:1. I would be surprised if you’re cleaning houses effectively at this ratio.

Personally, I find percentages to be more useful than ratios. Especially since we use percentages to measure SH concentration.

To calculate percentage, divide 16 by 640 = .025
Multiply by 100 = 2.5%
Or multiply by SH strength to get final concentration: .025 * 12.5 = 0.3125% SH hitting the siding.


I done terrible in English class. I forget punctuation. As far as specs go. I have a Honda gx360 with an hp5535 pump. Running at 5.5gpm at 3500psi. Believe my injector has 2.3 written on side of it. Injector came with my setup so not really sure about it. The pace I bought my equipment the guys told me it draws 20:1 and from my test seemed right. But I’m not sure.


@Ikii my bucket test filled 5 gallons in a minute and pulled 32oz from the injector sorry for typo.


My comments on grammar have been excessive. I apologize.

Yeah, 32 oz puts you right around 20:1 (technically 19.5:1, but that’s splitting hairs, tbh)


Well now we know.
Once you know your volume, it will be easier for you to work on your %s.
Cause, like @Infinity stated, your cleaning is based on % or ratios of concentration.
I used to be worried about that long time ago
Now i just eyeball it, and see how much volume i need so i dont waste.
SH is cheap, chemicals are cheap. The equipment and our time isnt


@infinity I just done my math the way you said. I can only get 10%sh in Florida. So I did 32oz draw rate.l divided by640 and came up with 0.5. then I done the math with sh percentage. As you told me so straight sh comes to 1 percent am I correct?




Sorry that was a typo I pulled 32oz in 1 minute.


Well since double checking my math as @infinity told me to do. With 10% sh. I am pulling about 0.01%. So in conclusion my injector sucks. Time to buy anoth injector. From my math.


If your using 10% SH and drawing at 20-1 then your percentage of SH hitting the surface is 0.5 %

I like to be more up around .8 %. But every environment is different


Get rid of the percent

10 SH / 20 (draw rate) = 0.5 (% of SH) coming out of the gun


I’ve used .5% before but only in the summer. And even then I had to apply twice if it’s dirty. I live in NC


And not on stucco…


I live in Florida and my injector was putting .75 on the wall and it wouldn’t even touch the stucco. X-Jet works wonders.


There are very few stucco homes where I am…I think I’ve only seen one with a stucco front so I never have to worry about it. In FL however where I lived in Melbourne every home was mostly stucco and some brick.


Wow. How about if it doesn’t come clean, add more bleach or Xjet. Your draw rate is irrelevant in real world applications.


Thanks @Innocentbystander