PH A Basic explanation

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TNToothpick

TNToothpick

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So is this possibly an issue I am seeing in my first grow? I’m using FFOF with a little perlite added in and I’m using tap water with 110ppm and adjusting the ph down just a hair from ~7 to 6.5. I check the runoff and the ph will be close to that usually, but I have a soil test meter that will read ~6.5 after watering, but a day or 2 later it creeps up to 7.5-8 at times. Is that from buildup or what may be going on there?
 
Aqua Man

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So is this possibly an issue I am seeing in my first grow? I’m using FFOF with a little perlite added in and I’m using tap water with 110ppm and adjusting the ph down just a hair from ~7 to 6.5. I check the runoff and the ph will be close to that usually, but I have a soil test meter that will read ~6.5 after watering, but a day or 2 later it creeps up to 7.5-8 at times. Is that from buildup or what may be going on there?
I doubt that's from build up in such a short period. soil is a bit more difficult to diagnose because you don't know 100% what's in it and if you didn't test it to begin with then it's hard to say.
 
MIMedGrower

MIMedGrower

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So is this possibly an issue I am seeing in my first grow? I’m using FFOF with a little perlite added in and I’m using tap water with 110ppm and adjusting the ph down just a hair from ~7 to 6.5. I check the runoff and the ph will be close to that usually, but I have a soil test meter that will read ~6.5 after watering, but a day or 2 later it creeps up to 7.5-8 at times. Is that from buildup or what may be going on there?


If you mean a cheap probe ph meter or one of the 3 way double probe meters you stick in the soil they can be extremely inaccurate.

Mine pretty much always reads 7.0 but my soil is a really 6.2.

Better to check runoff regularly for an average or to see it changing over time or even better taking a sample of soil and mixing it with distilled water and read the liquid resulting woth ph drops, strips or a quality ph pen.

The soil probe meters that work well used by field workers costs around $400. And still requires distilled water in the soil for a proper reading.

i use gen hydro ph drops. If the color reads in range light yellow green to green I know im ok.
 
TNToothpick

TNToothpick

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If you mean a cheap probe ph meter or one of the 3 way double probe meters you stick in the soil they can be extremely inaccurate.

Mine pretty much always reads 7.0 but my soil is a really 6.2.

Better to check runoff regularly for an average or to see it changing over time or even better taking a sample of soil and mixing it with distilled water and read the liquid resulting woth ph drops, strips or a quality ph pen.

The soil probe meters that work well used by field workers costs around $400. And still requires distilled water in the soil for a proper reading.

i use gen hydro ph drops. If the color reads in range light yellow green to green I know im ok.

ok yeah it is one of the cheap probe meters. I figured the ph reading would be pretty inaccurate. I mostly got it for the moisture reading. It helps so I don’t have to move plants around to lift them all the time to check.
 
Oa.ahhu

Oa.ahhu

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So is this possibly an issue I am seeing in my first grow? I’m using FFOF with a little perlite added in and I’m using tap water with 110ppm and adjusting the ph down just a hair from ~7 to 6.5. I check the runoff and the ph will be close to that usually, but I have a soil test meter that will read ~6.5 after watering, but a day or 2 later it creeps up to 7.5-8 at times. Is that from buildup or what may be going on there?
When you ph your water how long do you let it circulate, and let the ph/temp equalize ?
 
TNToothpick

TNToothpick

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When you ph your water how long do you let it circulate, and let the ph/temp equalize ?

Well I fill up 1 gallon jugs with tap water and let it sit for a day, check ph then adjust it down with lemon juice. Usually just shake it up after adding lemon and let it sit for a few minutes then recheck.
 
Oa.ahhu

Oa.ahhu

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Well I fill up 1 gallon jugs with tap water and let it sit for a day, check ph then adjust it down with lemon juice. Usually just shake it up after adding lemon and let it sit for a few minutes then recheck.
I would try out something that wont raise your ppm when you're adjusting the ph. I would get a wide mouth container and a couple 10l airstones and let it circulate and reach homeostasis (assuming we aren't going to consider the alkalinity of the water) for 30 minutes to an hour. Once it has leveled off pretty good then dump.I run water through a 3 stage carbon ->carbon->tds filter to get rid of the chlorine while also lowering the ppms of the water. Then I drop an airstone in it while prepping the nutes/etc drop the nutes in and then let it level off and ph it to 6.3-6.5.
Hopefully it's not too much rambling! Cheers
 
MIMedGrower

MIMedGrower

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ok yeah it is one of the cheap probe meters. I figured the ph reading would be pretty inaccurate. I mostly got it for the moisture reading. It helps so I don’t have to move plants around to lift them all the time to check.


I think the moisture meter works fine. I use mine to doublecheck for watering time and also to scratch up the surface of the soil to help water penetrate evenly.

And the light meter does show when my bulbs have degraded. Just not too accurately.
 
TNToothpick

TNToothpick

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----->Semi spoiler alert


Here is a good read about how the internal ph(s) of the plant is how it maintains equilibrium (which is controlled predominantly by N uptake )(nitrate & ammonium). Definitely was interesting .
I would try out something that wont raise your ppm when you're adjusting the ph. I would get a wide mouth container and a couple 10l airstones and let it circulate and reach homeostasis (assuming we aren't going to consider the alkalinity of the water) for 30 minutes to an hour. Once it has leveled off pretty good then dump.I run water through a 3 stage carbon ->carbon->tds filter to get rid of the chlorine while also lowering the ppms of the water. Then I drop an airstone in it while prepping the nutes/etc drop the nutes in and then let it level off and ph it to 6.3-6.5.
Hopefully it's not too much rambling! Cheers

Not too much rambling at all! All of the valuable info is much appreciated!
 
Frankster

Frankster

Never trust a doctor who's plants have died.
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This is not a "basic" understanding of pH. It was a difficult read, at best.

I'm sorry, but I've got 3 years college of organic, inorganic and bio chemisty, (one year each) I was a top student in all of those classes (my biochem was like 60 students, (Future doctors, pharmacist, chemist, nurse practitioners)

That said, there's lot's of good, useful information in here. My intentions are certainly not to bomb your thread here, but I would suggest you "clean up" your idea's and thought structure of how you try and convey information.

First, you don't even give a clear indication of what PH actually is:
The Fundaments:
measurement of hydrogen ions in solution. ie. H+ vs OH- (think protons and electons).
In chemistry, Ph is an exponential scale used to specify how acidic or basic a water-based solution is. Acidic solutions have a lower pH, while basic solutions have a higher pH ie. 6.2 is twice as acidic as 6.3...
6.0 is 100,000x times more ACIDIC THAN 6.5...
pure water is neither acidic nor basic and has a pH of 7.
At 25 °C, solutions with a pH less than 7 are acidic, and solutions with a pH greater than 7 are basic.(alkaline).

(It's a fundamental way plants "channel" atoms around for building things, the +/- allows atoms to be moved along an eletrical gradient, much like matter/energy are related in electrical energy). This is a pipeline that allow chemicals to either store or release energy.

Buffer capacity is defined as the moles ie(measurement of atoms) of an acid or base necessary to change the pH of a solution by 1, divided by the pH change and the volume of buffer in liters. A buffer resist changes in pH due to the addition of an acid or base though CONSUMPTION OF THE BUFFER.

Personally, for soil grows, I check and adjust the pH of every single liter of solution added to my planters. For me, getting a good handle on this has been paramount to my success in growing the highest quality cannabis. Furthermore, I adjust that pH based upon the needs of the plant, and it's status. ESPECIALLY, if any formulas are added to the solution, the more solids suspended, ie(the more fertilizer added) the more critical pH becomes. Water without anything in it, is NEUTRAL, and doesn't require pH adjustments, because it's not got much of anything in it, it might be slightly one way or another, but that's irrelevant, because there's simply not enough solids dissolved in it, ie(molar mass) to have a "buffered" effect.

While it might not be necessary to pH adjust simple "watering' of a plant, when nothing is added to it, it's still a good practice, as a balanced pH is CRITICAL to plant metabolism and anabolism.
 
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Oa.ahhu

Oa.ahhu

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This is not a "basic" understanding of pH. It was a difficult read, at best.

I'm sorry, but I've got 3 years college of organic, inorganic and bio chemisty, (one year each) I was a top student in all of those classes (my biochem was like 60 students, (Future doctors, pharmacist, chemist, nurse practitioners)

That said, there's lot's of good, useful information in here. My intentions are certainly not to bomb your thread here, but I would suggest you "clean up" your idea's and thought structure of how you try and convey information.

First, you don't even give a clear indication of what PH actually is:
The Fundaments:
measurement of hydrogen ions in solution. ie. H+ vs OH- (think protons and electons).
In chemistry, Ph is an exponential scale used to specify how acidic or basic a water-based solution is. Acidic solutions have a lower pH, while basic solutions have a higher pH ie. 6.2 is twice as acidic as 6.3...
6.0 is 100,000x times more ACIDIC THAN 6.5...
pure water is neither acidic nor basic and has a pH of 7.
At 25 °C, solutions with a pH less than 7 are acidic, and solutions with a pH greater than 7 are basic.(alkaline).

Buffer capacity is defined as the moles ie(measurement of atoms) of an acid or base necessary to change the pH of a solution by 1, divided by the pH change and the volume of buffer in liters. A buffer resist changes in pH due to the addition of an acid or base though CONSUMPTION OF THE BUFFER.

Personally, for soil grows, I check and adjust the pH of every single liter of solution added to my planters. For me, getting a good handle on this has been paramount to my success in growing the highest quality cannabis. Furthermore, I adjust that pH based upon the needs of the plant, and it's status. ESPECIALLY, if any formulas are added to the solution, the more solids suspended, the more critical pH becomes.

While it might not be necessary to pH adjust simple "watering' of a plant, when nothing is added to it, it's still a good practice, as a balanced pH is CRITICAL to plant metabolism and anabolism.
This is not a "basic" understanding of pH. It was a difficult read, at best.

I'm sorry, but I've got 3 years college of organic, inorganic and bio chemisty, (one year each) I was a top student in all of those classes (my biochem was like 60 students, (Future doctors, pharmacist, chemist, nurse practitioners)

That said, there's lot's of good, useful information in here. My intentions are certainly not to bomb your thread here, but I would suggest you "clean up" your idea's and thought structure of how you try and convey information.

First, you don't even give a clear indication of what PH actually is:
The Fundaments:
measurement of hydrogen ions in solution. ie. H+ vs OH- (think protons and electons).
In chemistry, Ph is an exponential scale used to specify how acidic or basic a water-based solution is. Acidic solutions have a lower pH, while basic solutions have a higher pH ie. 6.2 is twice as acidic as 6.3...
6.0 is 100,000x times more ACIDIC THAN 6.5...
pure water is neither acidic nor basic and has a pH of 7.
At 25 °C, solutions with a pH less than 7 are acidic, and solutions with a pH greater than 7 are basic.(alkaline).

Buffer capacity is defined as the moles ie(measurement of atoms) of an acid or base necessary to change the pH of a solution by 1, divided by the pH change and the volume of buffer in liters. A buffer resist changes in pH due to the addition of an acid or base though CONSUMPTION OF THE BUFFER.

Personally, for soil grows, I check and adjust the pH of every single liter of solution added to my planters. For me, getting a good handle on this has been paramount to my success in growing the highest quality cannabis. Furthermore, I adjust that pH based upon the needs of the plant, and it's status. ESPECIALLY, if any formulas are added to the solution, the more solids suspended, ie(the more fertilizer added) the more critical pH becomes. Water without anything in it, is NEUTRAL, and doesn't require pH adjustments, because it's not got much of anything in it, it might be slightly one way or another, but that's irrelevant, because there's simply not enough solids dissolved in it, ie(molar mass) to have a "buffered" effect.

While it might not be necessary to pH adjust simple "watering' of a plant, when nothing is added to it, it's still a good practice, as a balanced pH is CRITICAL to plant metabolism and anabolism.
He explained ph and alkalinity in a pretty simple/useful way for the purpose it's being used for. I also ph my water everytime I feed so not disagreeing with ya there , thank you for the info. Cant ever learn enough .
 
MIMedGrower

MIMedGrower

17,190
438
This is not a "basic" understanding of pH. It was a difficult read, at best.

I'm sorry, but I've got 3 years college of organic, inorganic and bio chemisty, (one year each) I was a top student in all of those classes (my biochem was like 60 students, (Future doctors, pharmacist, chemist, nurse practitioners)

That said, there's lot's of good, useful information in here. My intentions are certainly not to bomb your thread here, but I would suggest you "clean up" your idea's and thought structure of how you try and convey information.

First, you don't even give a clear indication of what PH actually is:
The Fundaments:
measurement of hydrogen ions in solution. ie. H+ vs OH- (think protons and electons).
In chemistry, Ph is an exponential scale used to specify how acidic or basic a water-based solution is. Acidic solutions have a lower pH, while basic solutions have a higher pH ie. 6.2 is twice as acidic as 6.3...
6.0 is 100,000x times more ACIDIC THAN 6.5...
pure water is neither acidic nor basic and has a pH of 7.
At 25 °C, solutions with a pH less than 7 are acidic, and solutions with a pH greater than 7 are basic.(alkaline).

Buffer capacity is defined as the moles ie(measurement of atoms) of an acid or base necessary to change the pH of a solution by 1, divided by the pH change and the volume of buffer in liters. A buffer resist changes in pH due to the addition of an acid or base though CONSUMPTION OF THE BUFFER.

Personally, for soil grows, I check and adjust the pH of every single liter of solution added to my planters. For me, getting a good handle on this has been paramount to my success in growing the highest quality cannabis. Furthermore, I adjust that pH based upon the needs of the plant, and it's status. ESPECIALLY, if any formulas are added to the solution, the more solids suspended, ie(the more fertilizer added) the more critical pH becomes. Water without anything in it, is NEUTRAL, and doesn't require pH adjustments, because it's not got much of anything in it, it might be slightly one way or another, but that's irrelevant, because there's simply not enough solids dissolved in it, ie(molar mass) to have a "buffered" effect.

While it might not be necessary to pH adjust simple "watering' of a plant, when nothing is added to it, it's still a good practice, as a balanced pH is CRITICAL to plant metabolism and anabolism.


Good explanation but i must say to your last comment “not always”.

You must take alkalinity in to account. Most water alone unless extremely alkaline or acidic will not change the ph of a buffered potting soil no matter how much you pour through.

If you constantly add acid to water that doesnt need acidifying eventually it will build up and acidify the medium. Same goes for ph up. If you use ph up regularly it is like adding a bit of lime (calcium) to the pot every time and eventually it will build up and raise medium ph.


Much better advice to know the alkalinity of our source water and how it reacts with our medium and nutrients and adjust or not from there.

It is also more advisable to add nutrients to tap water in an amount that gets the final ph in range for proper uptake. Than to constantly adjust an improper mixture.

And really for very alkaline water (hard) it is better to mix down to 150 ppm with ro filtered water than to add acid to neutralize the calcium.
 
Aqua Man

Aqua Man

26,480
638
This is not a "basic" understanding of pH. It was a difficult read, at best.

I'm sorry, but I've got 3 years college of organic, inorganic and bio chemisty, (one year each) I was a top student in all of those classes (my biochem was like 60 students, (Future doctors, pharmacist, chemist, nurse practitioners)

That said, there's lot's of good, useful information in here. My intentions are certainly not to bomb your thread here, but I would suggest you "clean up" your idea's and thought structure of how you try and convey information.

First, you don't even give a clear indication of what PH actually is:
The Fundaments:
measurement of hydrogen ions in solution. ie. H+ vs OH- (think protons and electons).
In chemistry, Ph is an exponential scale used to specify how acidic or basic a water-based solution is. Acidic solutions have a lower pH, while basic solutions have a higher pH ie. 6.2 is twice as acidic as 6.3...
6.0 is 100,000x times more ACIDIC THAN 6.5...
pure water is neither acidic nor basic and has a pH of 7.
At 25 °C, solutions with a pH less than 7 are acidic, and solutions with a pH greater than 7 are basic.(alkaline).

Buffer capacity is defined as the moles ie(measurement of atoms) of an acid or base necessary to change the pH of a solution by 1, divided by the pH change and the volume of buffer in liters. A buffer resist changes in pH due to the addition of an acid or base though CONSUMPTION OF THE BUFFER.

Personally, for soil grows, I check and adjust the pH of every single liter of solution added to my planters. For me, getting a good handle on this has been paramount to my success in growing the highest quality cannabis. Furthermore, I adjust that pH based upon the needs of the plant, and it's status. ESPECIALLY, if any formulas are added to the solution, the more solids suspended, ie(the more fertilizer added) the more critical pH becomes. Water without anything in it, is NEUTRAL, and doesn't require pH adjustments, because it's not got much of anything in it, it might be slightly one way or another, but that's irrelevant, because there's simply not enough solids dissolved in it, ie(molar mass) to have a "buffered" effect.

While it might not be necessary to pH adjust simple "watering' of a plant, when nothing is added to it, it's still a good practice, as a balanced pH is CRITICAL to plant metabolism and anabolism.
Appreciate the feed back and I would agree with what you have said. But imo thats a more advanced version. I tried to stay away from the ion exchange, temp impact and other factors which are important but felt it would make it a bit to complex for the home newbie grower.

The acids used in ph down hardly last in the soil and really offer almost no staying power to ph easily seen in the fact trying to lower the ph of an alkaline soil with acid does not work well at all. So we can agree to disagree there. I feel like a much better option is to have a properly amended soil.

Absolutely the plant itself and type of nutrients and thier impact can be taken into account and should be. But where do we stop with a basic explanation? I chose to leave this out. By the time you get into iron and ammonia lower soil pH and cation exchange it's to much.

I'm a highschool dropout so maybe it shows but I only intended it to be a very basic starting point for a new grower. Non the less I do agree with what you have said and with your knowledge I would gladly sticky a more in depth thread if you don't mind taking the time to do so.
 
Aqua Man

Aqua Man

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Good explanation but i must say to your last comment “not always”.

You must take alkalinity in to account. Most water alone unless extremely alkaline or acidic will not change the ph of a buffered potting soil no matter how much you pour through.

If you constantly add acid to water that doesnt need acidifying eventually it will build up and acidify the medium. Same goes for ph up. If you use ph up regularly it is like adding a bit of lime (calcium) to the pot every time and eventually it will build up and raise medium ph.


Much better advice to know the alkalinity of our source water and how it reacts with our medium and nutrients and adjust or not from there.

It is also more advisable to add nutrients to tap water in an amount that gets the final ph in range for proper uptake. Than to constantly adjust an improper mixture.

And really for very alkaline water (hard) it is better to mix down to 150 ppm with ro filtered water than to add acid to neutralize the calcium.
Yeah I agree here. I would rather build a soil to my source water and nutrients. Far more reliable and stable than using a ph down to try to change the ph in the soil
 
MIMedGrower

MIMedGrower

17,190
438
Yeah I agree here. I would rather build a soil to my source water and nutrients. Far more reliable and stable than using a ph down to try to change the ph in the soil


Thats why i used ocean forest and pure blend pro grow for so long. It just always all balanced out so if i saw acidic ph i knew ot was from too much nutes. Not too much ph down.

I tried to explain this to @Beachwalker a few times. If you needlessly add ph down eventually you will need to raise ph. I believe this is why some growers need to add extra lime to an already perfectly buffered soil.

And when i added extra lime it just raised my ph out of range eventually.
 
Aqua Man

Aqua Man

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638
And to be honest there are not a many alkaline sources in the nutrients we use. So a buffered soil usually keeps its ph for as long as a grow goes atleast. Usually the issue is just that the makeups of fertalizer we use are generally acidic.
Thats why i used ocean forest and pure blend pro grow for so long. It just always all balanced out so if i saw acidic ph i knew ot was from too much nutes. Not too much ph down.

I tried to explain this to @Beachwalker a few times. If you needlessly add ph down eventually you will need to raise ph. I believe this is why some growers need to add extra lime to an already perfectly buffered soil.

And when i added extra lime it just raised my ph out of range eventually.
I agree with ya. Nutrients are generally acidic enough. It all depends on how you buffer the soil. High alkaline water source little bit of lime. Using RO you gonna need more. I think another reason ppl see different soil pH with same products. That and the same label doesn't mean it's going to be from the same batch.
 
MIMedGrower

MIMedGrower

17,190
438
Appreciate the feed back and I would agree with what you have said. But imo thats a more advanced version. I tried to stay away from the ion exchange, temp impact and other factors which are important but felt it would make it a bit to complex for the home newbie grower.

The acids used in ph down hardly last in the soil and really offer almost no staying power to ph easily seen in the fact trying to lower the ph of an alkaline soil with acid does not work well at all. So we can agree to disagree there. I feel like a much better option is to have a properly amended soil.

Absolutely the plant itself and type of nutrients and thier impact can be taken into account and should be. But where do we stop with a basic explanation? I chose to leave this out. By the time you get into iron and ammonia lower soil pH and cation exchange it's to much.

I'm a highschool dropout so maybe it shows but I only intended it to be a very basic starting point for a new grower. Non the less I do agree with what you have said and with your knowledge I would gladly sticky a more in depth thread if you don't mind taking the time to do so.


High school bored the crap out of you too?

I almost never went but later negotiated for my diploma with the superintendent of schools.

I arranged if i got at least B’s on my final exams i get a diploma despite my extensive absence.

I got all A’s. America public school education is a bad joke.
 
Aqua Man

Aqua Man

26,480
638
High school bored the crap out of you too?

I almost never went but later negotiated for my diploma with the superintendent of schools.

I arranged if i got at least B’s on my final exams i get a diploma despite my extensive absence.

I got all A’s. America public school education is a bad joke.
Yup dropped out at 16 moved out and went to work. Regretting since but I never stopped loving learning.. only thing is I learn about what I want. When I retire I'm prob going back to school
 
Beachwalker

Beachwalker

7,055
313
Thats why i used ocean forest and pure blend pro grow for so long. It just always all balanced out so if i saw acidic ph i knew ot was from too much nutes. Not too much ph down.

I tried to explain this to @Beachwalker a few times. If you needlessly add ph down eventually you will need to raise ph. I believe this is why some growers need to add extra lime to an already perfectly buffered soil.

And when i added extra lime it just raised my ph out of range eventually.
That may work for you, but as I've explained before my waters 8.9 out the tap, can't use it that high, plants don't like it

I haven't had my pH go below 6.1 in about a year or more, ever since I started using the citric acid instead of the commercial products
 
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