# Who checks their pH of their spray solution?



## Colonel K0rn (Jul 4, 2017)

Since this is applicable across Cool Season and Warm Season lawns, I figured this would be the best subforum to put this thread in, and also ask for some input from members. I watched Pete Denny's latest video today, on how to kill weeds. And I'm thinking to myself, "Well, duh, it's not that hard." But then he showed a step in his mixing that I have read in the labels of some of the herbicides that I use, but I haven't even considered putting into practice in my own routines. He checked the pH of his 3-way with a handheld pH meter, and adjusted the pH down with some citric acid.

I had that "Ahhh" moment when I thought that I might be missing a key step in increasing the efficacy of my products that I'm putting down, and that I've always trusted what came out of the tap to be good to go on my lawn. Well, I am pretty sure that my tap water is around 7, but with the mix that he made, he was aiming for a target pH of 5. I understand the science behind why, but it never dawned on me to take this step.

I found several articles online from UT, A&M, PSU and a few other colleges. I wanted your input, and let's see if we can get another resource together.


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## Mightyquinn (Jan 31, 2017)

Colonel K0rn said:


> Since this is applicable across Cool Season and Warm Season lawns, I figured this would be the best subforum to put this thread in, and also ask for some input from members. I watched Pete Denny's latest video today, on how to kill weeds. And I'm thinking to myself, "Well, duh, it's not that hard." But then he showed a step in his mixing that I have read in the labels of some of the herbicides that I use, but I haven't even considered putting into practice in my own routines. He checked the pH of his 3-way with a handheld pH meter, and adjusted the pH down with some citric acid.
> 
> I had that "Ahhh" moment when I thought that I might be missing a key step in increasing the efficacy of my products that I'm putting down, and that I've always trusted what came out of the tap to be good to go on my lawn. Well, I am pretty sure that my tap water is around 7, but with the mix that he made, he was aiming for a target pH of 5. I understand the science behind why, but it never dawned on me to take this step.
> 
> I found several articles online from UT, A&M, PSU and a few other colleges. I wanted your input, and let's see if we can get another resource together.


Hey Colonel, this has crossed my mind too in the past but I have never pursued it any further. I would be curious to see what my spray solution pH would be but I think it mainly pertains to weed control and it's something I don't do very often. Looks like the pH testers can be found on Amazon for less than $20 :thumbup:


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## gene_stl (Oct 29, 2017)

A very interesting consideration. 
I think I would trust these: 
https://www.walmart.com/ip/pH-Test-Strips-120ct-Quick-and-Accurate-Results-Check-Your-Acidic-Alkaline/144207438
before I would trust a $20 pH meter unless I had checked the calibration of the cheap meter. (sometimes cheapo stuff is fine) A pH meter is essentially a voltmeter. I even saw some for $11.
We used to use these in the lab. Very old time reputable product:
https://www.amazon.com/Micro-Essential-Lab-3110M18EA-Dispenser/dp/B00LY1KIWY/ref=zg_bs_4989325011_4?_encoding=UTF8&psc=1&refRID=KTXYV4SW80CAWB5HP32A
Available in various ranges.

Tap water is going to be sevenish most places. And having just lately been reading herbicide labels I didn't notice any recommendations about buffering the pH (Tenacity , Quinclorac , Carfentrazone, Q4Plus) so I am not sure why he wants to adjust it in the acid direction. Although I don't doubt he knows what he is doing.

A quick search yield these:
https://ag.purdue.edu/btny/weedscience/documents/water_quality.pdf
which confirms that you usually want things a little acid for glyphosate and 2,4,D. The devil is always in the details. There are also some that want to be alkaline. The article references using ammonium sulfate to acidify.
https://oregonstate.edu/dept/nursery-weeds/feature_articles/spray_tank/spray_tank.htm
https://ag.umass.edu/greenhouse-floriculture/fact-sheets/effects-of-ph-on-pesticides-growth-regulators


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## g-man (Jun 15, 2017)

I always thought about hard water. At my house we are at ~24 grains. I don't like to irrigate with it, but it will be expensive to treat it.


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## gene_stl (Oct 29, 2017)

Well those articles all are in agreement that it is good to acidify the water(especially when its hard) for most liquid products. An exception are sulfonylurea fungicides. Those seem to be better in alkaline solution (add sodium bicarb or carbonate)


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## MasterMech (Sep 24, 2017)

g-man said:


> I always thought about hard water. At my house we are at ~24 grains. I don't like to irrigate with it, but it will be expensive to treat it.


Are you having trouble irrigating with hard water? Equipment or plant related? I could see where irrigating with soft water would be expensive and hard on your softener, but the few gallons used to make a spray batch is nothing.


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## gene_stl (Oct 29, 2017)

I watched the Professor Pete video referenced at the top of this thread and he mentions that he is adjusting pH to make his adjuvant work better. If the detergents are ionic adding some acidity would help. But it also makes the herbicides work better too by preventing dissociation into inactive molecules..


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## Colonel K0rn (Jul 4, 2017)

gene_stl said:


> I watched the Professor Pete video referenced at the top of this thread and he mentions that he is adjusting pH to make his adjuvant work better. If the detergents are ionic adding some acidity would help. But it also makes the herbicides work better too by preventing dissociation into inactive molecules..


Them's a lot of $5 words my friends...  Glad I did pretty good in chemistry.


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## g-man (Jun 15, 2017)

MasterMech said:


> Are you having trouble irrigating with hard water? Equipment or plant related? I could see where irrigating with soft water would be expensive and hard on your softener, but the few gallons used to make a spray batch is nothing.


I dont like to throw more calcium into my calcium rich soil. If I apply 1in of water, will need 628 gallons / 1k sqft. For my 5,678 sqft, that's 3560 gallons (~4.7 CCF). I cant treat that much water from my current softener (at 24 grains of hardness).

For spray batch, the minor problem is that my outside spigots are hard water supply. I would have to get the water from the kitchen (wife will not be happy with lawn chemicals in the house). I plan to pipe one spigot from the treated side to the garage.


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## MasterMech (Sep 24, 2017)

g-man said:


> MasterMech said:
> 
> 
> > Are you having trouble irrigating with hard water? Equipment or plant related? I could see where irrigating with soft water would be expensive and hard on your softener, but the few gallons used to make a spray batch is nothing.
> ...


If your hot water heater is in the garage, it should have a drain in the bottom of it. (assuming yours is not tankless) For a 4-5 gallon spray batch, you won't get more than lukewarm water from it and it should be treated. Word of caution, those drains can be quite fragile if it's plastique and never been operated, up to you to decide if it's operable or not. If you do in fact install a treated spigot, it should be quite useful for washing cars as well.

As far as treating your irrigation water, I've heard that all the sodium in traditionally softened water is a no-go but I have never tested that theory. Certain grass species will be more tolerant than others however.


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## gene_stl (Oct 29, 2017)

Water softeners substitute the Sodium in those big salt pills or grains for the Calcium and Magnesium. Because of the chemistry it takes two Sodium ions to remove one Calcium or Magnesium. This increases the salt content. I would think the hard water would be preferable. I am guessing from theory. 
As far as spray solutions are concerned using the softened water should be no problem and throwing in a about 2 oz of Ammonium Sulfate per ten gallons would lower the pH enough for most purposes.


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## gene_stl (Oct 29, 2017)

Water softeners substitute the Sodium in those big salt pills or grains for the Calcium and Magnesium. Because of the chemistry it takes two Sodium ions to remove one Calcium or Magnesium. This increases the salt content. I would think the hard water would be preferable. I am guessing from theory. 
As far as spray solutions are concerned using the softened water should be no problem and throwing in a about 2 oz of Ammonium Sulfate per ten gallons would lower the pH enough for most purposes.


> Them's a lot of $5 words my friends...  Glad I did pretty good in chemistry.


In the second grade I was dubbed "the mad scientist of McKnight school" Sixty years later I am still working repairing scientific instruments at a local university(including a bunch of lawn equipment :mrgreen . Can't jump out my skin :roll:  
After all what we are doing here is applied botany and biochemistry.


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