can't figure how much weed killer concentrate

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  #1  
Old 07-24-17, 03:07 PM
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can't figure how much weed killer concentrate

I have some lawn weed killer concentrate called Spectracide Weed Stop For Lawns Concentrate. According to directions, you can use sprayers of the type “CONCENTRATE-PLUS-WATER” SPRAYER (for sprayers that require the addition of water as well as concentrate prior to application). I have one of those type of sprayers, the type shown in the following link: https://www.amazon.com/Hudson-2203GT.../dp/B0050JRMKW On the sprayer it says "sprays 1-20 gallons".
The instructions printed on the sprayer are as follows:
"Step 1: Place proper amount of chemical (powder or liquid) into jar to make desired number of gallons to be sprayed. Fill jar with proper amount of water for gallons to be sprayed and mix well (see mixture example):
Mixture example: If chemical product calls for 1 tablespoon per gallon and you want 5 gallons of finished spray, place 5 tablespoons of product into jar and fill with water to the 5 gallon mark on side of jar.

Step 2: Attach sprayer head to jar to prevent any spillage. Firmly thread hose-end connector to the end of garden hose. Turn water valve (counterclockwise) to OFF position. Turn on water faucet.

Step 3: To spray your mixture turn the valve (clockwise) to the ON position. Valve must be fully open for best results. To water your plants turn back to the WATER position. To shut off water turn back to the OFF position."

On the side of the sprayer, there are two printed graduated scales. One scale is lines marked fluid ounce measurments and goes from 4 to 26. The other scale is 7 lines marked in 2 1/2 gallon line increments going from 2 1/2 gallons up to 20 gallons.

The instructions on the weed killer concentrate are as follows: "For sprayers that require the addition of water as well as concentrate prior to application:
1. From the following chart, determine amount of concentrate required to treat each 250 sq ft of lawn.
2. Pour concentrate into sprayer jar to the required “fl oz” level.
3. Then add the appropriate amount of water to the “gallons” level. Replace sprayer top on jar and shake well before spraying.
4. Attach sprayer to hose. Extend hose to the farthest area of lawn to be treated and work back toward faucet so that you do not walk over treated areas. Apply evenly to lawn.

250 sq ft to be treated
Type of Grass
Ounces of Concentrate
Gallons of Water
St. Augustine*, Bahia, Centipede
1/2
1
Bermuda, Bentgrass
2/3
1
Bluegrass, Fescue, Rye, Zoysia
1
1
1,000 sq ft to be treated
Type of Grass
Ounces of Concentrate
Gallons of Water
St. Augustine*, Bahia, Centipede
2
4
Bermuda, Bentgrass
2 2/3
4
Bluegrass, Fescue, Rye, Zoysia
4
4
5,000 sq ft to be treated
Type of Grass
Ounces of Concentrate
Gallons of Water
St. Augustine*, Bahia, Centipede
10
20
Bermuda, Bentgrass
13 1/3
20
Bluegrass, Fescue, Rye, Zoysia
20
20
8,000 sq ft to be treated
Type of Grass
Ounces of Concentrate
Gallons of Water
St. Augustine*, Bahia, Centipede
16
32
Bermuda, Bentgrass
21 1/3
32
Bluegrass, Fescue, Rye, Zoysia
32
32
EXAMPLE: To treat 1,000 sq ft of fescue, pour in concentrate to the 4 fl oz mark and add water to the 4 gal mark. Check the directions you received when you purchased your sprayer for further details on the proper use of your sprayer."

So my question would be, if I have bluegrass and my lawn measures 2000 square feet, how much of the concentrate do I pour into my sprayer? I'm way too confused by the directions.
Any answers/comments appreciated.
 

Last edited by sgull; 07-24-17 at 04:37 PM.
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  #2  
Old 07-24-17, 04:12 PM
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You need one ounce of concentrate per 250 feet of lawn for bluegrass. So, for a 2'000 foot lawn you need eight ounces of concentrate. Put 8oz of concentrate in your sprayer and add water to the 8 gallon line. Then the tough part is spraying your entire lawn and running out of chemical just as you finish the lawn while not missing any spots. To make it easier you can double the amount of water in your sprayer (fill to the 16 gallon line) then plan on going over your lawn twice using a different spraying pattern on the second pass.
 
  #3  
Old 07-24-17, 04:46 PM
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Thank you Pilot Dane. Now it'd be helpful if I had a breakdown of how you did the math on that. Because the square footage of 2000 for the lawn was my "estimate" without actually measuring. When I do actually take a measurement and find out the true square footage, if I had the math breakdown or perhaps "formula" maybe I can figure it up myself. Plus I gotta do the backyard too and that's different square footage so will require more of the math again...
 
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Old 07-25-17, 04:36 AM
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The labeling was for increments of 250 square feet. I started with the total square footage 2'000 and divided that by 250 which will tell you how many 250ft sections there are in 2'000. In this case 2'000/250=8. If your lawn is actually 2'500ft then it will be 2'500/250=10.

The next math is easy since it's one ounce per 250 so 8*1=8. If you have a different grass and need a different ratio say .75 ounce per 250 feet then you would multiply 8 times .75 which gives you 6 ounces of concentrate 8*.75=6.
 
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Old 07-25-17, 08:17 AM
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I've used that stuff (and other brands similarly vague about application amounts) before and had to guess. I figured out how much should be applied to my lawn but then had to monkey with the rate on the sprayer. The weeds didn't suffer as much as I thought they should, so I bought more (had exactly run out when I got to the end of the lawn) and upped the rate so I applied more per square foot, figuring I had come out low on that number the first time.

At least now, if I use it again, I know what numbers to use.
 
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Old 07-25-17, 08:25 AM
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I figured out how much should be applied to my lawn but then had to monkey with the rate on the sprayer.
Well my el-cheapo sprayer is the type that doesn't have the dial on the sprayer nozzle so at least I can't monkey with that rate.

Also, I notice in the reviews of that sprayer that unless you add a couple of o-rings to it beforehand, it'll be leaking badly so I'll need to go get some proper size o-rings first. Then I gotta take a good measurement of the square footage of the lawn(s), then I gotta determine for certain what type of grass I actually have instead of guessing that it's bluegrass, then do the math as per Pilot Dane, then do a test/trial run with that sprayer using just water so I can see how it works exactly.
 

Last edited by sgull; 07-25-17 at 08:43 AM.
  #7  
Old 07-25-17, 12:09 PM
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Okay now I'm unclear about how the sprayer works with the concentrate. As trial I filled the sprayer about halfway with water then hooked up the hose to it and sprayed. What happens is the sprayer sprays but gradually fills with water as it's doing so, and just keeps filling to the top and even when it fills all the way to the top just keeps spraying. So I don't really understand how you can tell when the concentrate/mix has been depleted and so when to stop so you're not just spraying water.
 
  #8  
Old 07-25-17, 12:43 PM
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I think you need a new sprayer. Maybe this one can be fixed but they're cheap enough I wouldn't bother.
 
  #9  
Old 07-25-17, 01:03 PM
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It's a brand new sprayer, never been used. Despite the reviews I read saying it leaks unless new Orings are installed, with my trial I saw no sign of such leakage. I don't think there's anything wrong with the sprayer itself, it's just that I'm unfamiliar with how it's supposed to work, specifically why it would just gradually fill up with water while spraying and how I'd tell when/whether the concentrate/mix inside has been depleted.
 
  #10  
Old 07-25-17, 01:24 PM
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OK, all I know is that's not how mine works - the fluid you pour into it gets depleted as you spray so you know to refill when it's empty.
 
  #11  
Old 07-25-17, 01:48 PM
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I had a feeling this was gonna be complicated from the start. For me, anyway.
 
  #12  
Old 07-26-17, 11:37 PM
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So after reading up some on how these sprayers are supposed to work, it is apparent that mine is missing the necessary tube that should extend down into the bottle from the hole in the bottom of the lid.
 
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