Enlighten me on the proper way to measure pH run-off please

[Mark Gordan Smith]

Yay or nay?

starting off with the highest quality soil that I could find as my base, Roots Organic 101.

(edit) Possibly Aurora Innovations

 

[Emilya Green]

Yay or nay?


(edit) Possibly Aurora Innovations

IMHO, the best soil for the budget minded cannabis grower. And, it makes a great base for when you finally get tired of being a pawn of the nutrient companies, and go full natural living soil organic.

 

[Mark Gordan Smith]

I'll try and find a similar medium over my side of the pond.
I'll pleased that the OP started this thread....Happy New Growing to yer!

pawn of the nutrient companies

I recall Em's previous posts about organic mediums.
Of course for the real Noobie-noob the first thing is to iron out what is organic and what would make me a pawn.

Cal-mag....castings....MiracleGrow.....SubCool's SuperSoil.....Two pints of larger and a packet of crisps please.......
No, don't reply..I have to do something off my own bat.

 

[1969gtx]

Ok, they seem good. Color is excellent, and leaves reaching high! But, and there is always a but, what

about proper numbers for ppm and EC?

 

[Emilya Green]

about proper numbers for ppm and EC?

I find myself confused by your question.
I am assuming that you went out and got some nutes, but since you are working with soil, most of the soil nutrient lines measure things in ml or tbls per gallon... and many soil gardeners see no need to ever buy a ppm or EC meter.

Your plants are looking great, but I am curious which nutes you got and wondering if you got nutes made for hydro instead of an organic soil line.

 

[60's Old Timer]

I'm with you Emilya on this very knowledgeable & experienced data. We used the same concept in a small commercial vegetable greenhouse. Consistently checked & recorded the Hydro plants with auto testing equipment. In a separate area for the potted plants in enhanced soil, we only watered with pH'd water. I also asked why we tested the Hydro plants runoff and not the soil plants, I heard a response very similar to your explanation. This was in the late 90's and like you, I haven't heard any legitimate opposing positions. Ha, only a temporary basic wage clean & water interim job until construction projects picked up.

 

[fanleaf]

I know my opinions on soil runoff are not popular, but what I say here is accurate to the best of my knowledge and experience.

Measuring the runoff pH and the ppm of the runoff in soil, is totally meaningless. It is a waste of time and confuses new growers more than many of the other myths being propagated out here in the growing world.

First, lets logically look at how much runoff you choose to work with. You have the choice of measuring this slew at several points of questionable accuracy... barely any runoff [lets call it 2%], 10% or 20% runoff as some people suggest you should strive for every time. Logically answer this question for me: at which dilution level are your numbers accurate and actually represent something happening up in the soil? There is no standard to making this measurement as there is in a slurry test... so how can you feel confident that your numbers are even accurate? The answer is: you can't. Your number is meaningless.

Next, lets look at what this runoff is. Your soil is constantly breaking down into its organic components throughout the grow. Peat breaks down and sends the soil acidic. Limestone breaks down and sends the soil to the base side. Nutrients break up into the component minerals and salt and carbon. When you water to runoff, or do a flush, all of this debris is able to be washed out of the soil. Even with a 2% runoff, as significant amount of sludge is washed out with the excess water, just like a percolator making coffee in a coffee maker. Of course the water exiting at the bottom after picking up all of this debris is of a different pH than the water that you added at the top. Of course this runoff water has a higher ppm than what you applied at the top. Again, at what dilution level do you assign some sort of accuracy to these readings? How in the world does this number relate to what is happening up top in the soil other than to show you that some sort of breakdown is occurring?

A lot of the confusion that has resulted in this area has to do with the fact that what I am discussing here only has validity in soil. If you are running any sort of hydro method, in a medium that does not break down, there actually are useful measurements that can be made using the runoff, especially ppm... you can actually see how many of your nutes have been used by the plants in the solution. What happens in hydro however is not always valid in the soil world.

Most soils are designed to be buffered, and that means that they are designed to be at a base pH when they are dry. Soil designers set this base pH to the upper end of the soil pH range so that as the soil dries out, it will drift toward that base pH. If you correctly water at 6.3 pH, at that moment you have suspended a column of water in the soil roughly equivalent to 3/4 of the container size. That suspended column of water, hence your soil and everything in it, has no choice but to assume the pH of the liquid it is suspended in. Until your soil dries out and reaches the base pH, it is somewhere between the 6.3 that you watered at and the base pH of dry soil. This is exactly what we want, and why the soil was designed that way. If you water correctly at 6.3pH every time, your container of soil and the nutes you have applied are forced to drift through the entire pH range of 6.3-6.8 as the soil dries out, exactly what is recommended to do so as to pick up all of the 17 elements that our plants need to survive. Also, consider this. The pH of the soil at the bottom of the container that is still suspended in properly pH adjusted water below the water table line is different than the pH of the soil at the top of the container that has already dried out.

Thinking that your soil is at the wrong pH and then adjusting your inputted fluids to compensate for it, is actually shooting yourself in the foot and not taking advantage of all the science involved in creating your buffered soil. If you get too much out of the usable pH range because of your well meaning adjustment, your plants will suffer.

I hope this explanation helps to show how pH works in a container of soil and why it is important to water every time at 6.3 pH, and then let the soil do its thing, drifting your pH through the usable range. I hope this explanation also helps to allay fears caused by those well meaning experts who insist that runoff pH and ppm readings are somehow important to measure and then react to, in soil. These are the people who object most to my logical and scientific way of examining these subjects as well as what I teach and I invite any of those experts to explain to us here why what I say is wrong. I get better at explaining this all the time, and I really would like to hear a logical and scientific explanation as to why measuring soil runoff is not a total waste of time.

I second this. Measuring ph of the runoff is only measuring what your water stripped from the soil as it went through. Just needs some magnesium in that plant in the picture but Magnesium def may not be because there's a shortage of it but overwatering will create acidic wet spots when it rots things in the soil.

 

[1969gtx]

Sorry, I should have explained more.
The only nutes I have is one the hydro shop referred me to, which is Green Garden Magic One. I've only used it twice, but now they seem to be on track, I'll start again. I may switch to a known brand. My last watering was two days ago, and that was tap water, ph to 6.8 with 5ml of cal mag per gal. On a super slow watering, to run-off was only 1 gallon total for all 6 plants.
As far as the EC and PPM, I'm having trouble finding out what the numbers should be. My tap water is running these numbers, according to the new Apera pc60 gauge. Calibrated today.
7.61 ph
339 PPM
.24 EC
Where should they be, after adding nutes?
I feel like I've read too much, and am over complicating this.

 

[fanleaf]

no I would go with 6.5 ph the soil will drop it to 6.3 -6.2 witch is where you wanna be in soil , be sure too check run off every 2 waterings as the soil will slowly get to the point of the water going in will equal the water coming out .it is better to be slightly under than to be slightly over , it is easier to add to the soil ph but it is a bitch to get it to drop if your over.

Good soil pH is 6.2-6.8

 

[solareclipse]

I know my opinions on soil runoff are not popular, but what I say here is accurate to the best of my knowledge and experience.

Measuring the runoff pH and the ppm of the runoff in soil, is totally meaningless. It is a waste of time and confuses new growers more than many of the other myths being propagated out here in the growing world.

First, lets logically look at how much runoff you choose to work with. You have the choice of measuring this slew at several points of questionable accuracy... barely any runoff [lets call it 2%], 10% or 20% runoff as some people suggest you should strive for every time. Logically answer this question for me: at which dilution level are your numbers accurate and actually represent something happening up in the soil? There is no standard to making this measurement as there is in a slurry test... so how can you feel confident that your numbers are even accurate? The answer is: you can't. Your number is meaningless.

Next, lets look at what this runoff is. Your soil is constantly breaking down into its organic components throughout the grow. Peat breaks down and sends the soil acidic. Limestone breaks down and sends the soil to the base side. Nutrients break up into the component minerals and salt and carbon. When you water to runoff, or do a flush, all of this debris is able to be washed out of the soil. Even with a 2% runoff, as significant amount of sludge is washed out with the excess water, just like a percolator making coffee in a coffee maker. Of course the water exiting at the bottom after picking up all of this debris is of a different pH than the water that you added at the top. Of course this runoff water has a higher ppm than what you applied at the top. Again, at what dilution level do you assign some sort of accuracy to these readings? How in the world does this number relate to what is happening up top in the soil other than to show you that some sort of breakdown is occurring?

A lot of the confusion that has resulted in this area has to do with the fact that what I am discussing here only has validity in soil. If you are running any sort of hydro method, in a medium that does not break down, there actually are useful measurements that can be made using the runoff, especially ppm... you can actually see how many of your nutes have been used by the plants in the solution. What happens in hydro however is not always valid in the soil world.

Most soils are designed to be buffered, and that means that they are designed to be at a base pH when they are dry. Soil designers set this base pH to the upper end of the soil pH range so that as the soil dries out, it will drift toward that base pH. If you correctly water at 6.3 pH, at that moment you have suspended a column of water in the soil roughly equivalent to 3/4 of the container size. That suspended column of water, hence your soil and everything in it, has no choice but to assume the pH of the liquid it is suspended in. Until your soil dries out and reaches the base pH, it is somewhere between the 6.3 that you watered at and the base pH of dry soil. This is exactly what we want, and why the soil was designed that way. If you water correctly at 6.3pH every time, your container of soil and the nutes you have applied are forced to drift through the entire pH range of 6.3-6.8 as the soil dries out, exactly what is recommended to do so as to pick up all of the 17 elements that our plants need to survive. Also, consider this. The pH of the soil at the bottom of the container that is still suspended in properly pH adjusted water below the water table line is different than the pH of the soil at the top of the container that has already dried out.

Thinking that your soil is at the wrong pH and then adjusting your inputted fluids to compensate for it, is actually shooting yourself in the foot and not taking advantage of all the science involved in creating your buffered soil. If you get too much out of the usable pH range because of your well meaning adjustment, your plants will suffer.

I hope this explanation helps to show how pH works in a container of soil and why it is important to water every time at 6.3 pH, and then let the soil do its thing, drifting your pH through the usable range. I hope this explanation also helps to allay fears caused by those well meaning experts who insist that runoff pH and ppm readings are somehow important to measure and then react to, in soil. These are the people who object most to my logical and scientific way of examining these subjects as well as what I teach and I invite any of those experts to explain to us here why what I say is wrong. I get better at explaining this all the time, and I really would like to hear a logical and scientific explanation as to why measuring soil runoff is not a total waste of time.

Very usefull what u wrote.thanks.i was searching for something like this ...
I quess this ph ranges is for photoperiod plants.
But the meaning is same.if autos needs lower ph ,keep doing same thing change only the numbers.

 

[Emilya Green]

Very usefull what u wrote.thanks.i was searching for something like this ...
I quess this ph ranges is for photoperiod plants.
But the meaning is same.if autos needs lower ph ,keep doing same thing change only the numbers.

There is no reason that autos would need a different pH. Your proper pH range has only to do with the medium and the nutes you are using.

 

[FelipeBlu]

My tap water is running these numbers, according to the new Apera pc60 gauge. Calibrated today.
7.61 ph
339 PPM
.24 EC

Your tap water is quite Hard (high alkalinity), which means there’s at least abundant bicarbonate, and probably a lot of Ca, Mg (and possibly Fe) already in it. This may cause issues with nutrient lockout, since Potassium, in particular, will be in competition with the Ca and Mg.

You would probably be better off using RO water.

 

[NOOOBIENOT]

I agree but just 1 more question for you are you running a water softener on your home tap system ? if so a lot of those ppm`s may be salt from the softener , as I have softener here and was forced to get a R.O. system , amazon or ebay for $200 bucks and fairly easy to install or just buy r.o.water.

 

[Killian]

I had the same question about ph runoff. Emilya is spot on the runoff data is useless. However in my search for ph drift i could never find that it always drifts up. I'm not saying that's not accurate I just couldn't find it documented in any of my searches. I finally contacted Fox farms about their ocean forest soil and they dodged that question as well. However they did help me understand that their soil is buffered to range from 6.3 to 6.8 and as long as you ph in the same range then the ph in the soil will remain in that range. I still believe it's good practice to ph at the same number than to try and hit a range. Fox farms was also kind enough to explain how to test the ph in the soil with slurry tests. They also explained what to do to amend the soil. The only problem being it takes about thirty days for the amendments to kick in. Since I use new soil every grow that information was not helpful. By the time I Would get the soil amended the grow would be finished. Their response letter is in my current journal. It's an interesting read. I to was chasing my ph runoff and then lowering or raising it to compensate. Emilya was very kind to share her experience and information with me about ph and the use of calmag. I was using it to fix my deficiency but at way to low of a dose. I was using one teaspoon per gallon when I should have been using much more. My cal Mag deficiency continued getting worse. Thankfully I still had a nice harvest I just had to do a lot more trimming to get the ugly leaves out of my bud. Your plants are looking very healthy so your doing it right and asking the right questions.

 

[1969gtx]

Yes, it turns out the water is very hard. I never realized it. This was part of the reason I got the new ph/EC meter, to figure out where this water is at.
Noob, yes, I do have a softener, but the cold water in the kitchen is on a bypass. I'm going to start using different water.
I mixed up a gallon with 5ml of cal-mag, and 15 ml of nutes, ph'd to 6.45. It was .72 EC and Tds read 1.04 but not in PPM. It jumped to a different reading of ppt. No idea what that means.
I'm ditching the nutes, and the water.

 

[FelipeBlu]

I don’t know if this applies to your EC meter, but according to General Hydroponics:
To obtain an approximate sodium chloride TDS value, multiply the EC reading (in milliSiemens/cm) by 1000 and divide by 2.
Thus, if your EC is 1:
1*1000/2= 500 ppm.

 

[TorturedSoul]

Like the title says, I'm looking for the proper way to get my ph in balance. I thought I had a faulty ph meter, so I bought the more expensive Apera kit . I'm trying to set the water at 6.3.
Today, I did the slurry test, with extra mixed soil, mixing soil and water, letting it sit for 10 minutes, draining it off, measuring with both meters. I just used straight tap water for the test, ph of 7.3 going in. What came out was 7.1.

Well, that wasn't really a slurry test, then, technically speaking. Use distilled/DI water. Preferably from a sealed container - because when it's exposed to air, it sort of stops being 0 PPM water; absorbing CO₂ from the atmosphere causes the pH to shift towards the acidic side. Distilled water has no buffers, the soil will basically dictate the pH of your results.

People needing real scientific accuracy (IOW, lab setting) would perform such a test in one of those "glove box" devices, with the box pumped full of nitrogen, so the gasses in the atmosphere won't affect/change the water (and, therefore, the results). But that's getting pretty anal for our purposes, lol.

 

[TorturedSoul]

I don’t know if this applies to your EC meter, but according to General Hydroponics:
To obtain an approximate sodium chloride TDS value, multiply the EC reading (in milliSiemens/cm) by 1000 and divide by 2.
Thus, if your EC is 1:
1*1000/2= 500 ppm.

That kind of illustrates why "PPM" shouldn't be used... Different things will read differently. Err... Okay, that statement didn't really say much, lol. You'll notice that they stated sodium chloride TDS value. That's fine and dandy - if the only thing in your solution is table salt . If, on the other hand, your solution has multiple salts - or even just one, but a different one - then you cannot get an accurate total dissolved solids reading by using an EC meter, because each metallic salt will read differently. Some "TDS" meters will use a .7 conversion factor instead of a .5 one, because the manufacturer assumes that the salt you're testing will be... Well, I forget which one corresponds to that, but it's not NaCl. Anyway, they work fine for single-salt solutions. Mixtures of salts, not so much.

Uhh... Simplistic analogy: The mass of a modern United States nickel is five grams. If I told you that I had a pocket full of nickels that weighed 60 grams and asked you to figure out the face value of the coinage in my pocket, you'd immediately reply, "60 cents," because it'd be obvious that I had 12 nickels, yes? Okay, if I had a pocket full of mixed coinage weighing 215.226 grams, lol, and asked you to figure out the face value of my coins, well... You couldn't.

Which is why when they need to figure the answer to such a question (TDS of a solution containing a mixture of things), they'll take a sample, flash-dry it, and weigh the remaining solids on a very accurate scale. Which also has the benefit of taking the non-salt ingredients into consideration (which won't even bump an EC meter's reading).

That might be a slight simplification - but only a slight one.

 

[Emilya Green]

That kind of illustrates why "PPM" shouldn't be used... Different things will read differently. Err... Okay, that statement didn't really say much, lol. You'll notice that they stated sodium chloride TDS value. That's fine and dandy - if the only thing in your solution is table salt . If, on the other hand, your solution has multiple salts - or even just one, but a different one - then you cannot get an accurate total dissolved solids reading by using an EC meter, because each metallic salt will read differently. Some "TDS" meters will use a .7 conversion factor instead of a .5 one, because the manufacturer assumes that the salt you're testing will be... Well, I forget which one corresponds to that, but it's not NaCl. Anyway, they work fine for single-salt solutions. Mixtures of salts, not so much.

Uhh... Simplistic analogy: The mass of a modern United States nickel is five grams. If I told you that I had a pocket full of nickels that weighed 60 grams and asked you to figure out the face value of the coinage in my pocket, you'd immediately reply, "60 cents," because it'd be obvious that I had 12 nickels, yes? Okay, I have a pocket full of mixed coinage weighing 215.226 grams, lol, and asked you to figure out the face value of my coins, well... You couldn't.

Which is why when they need to figure the answer to such a question (TDS of a solution containing a mixture of things), they'll take a sample, flash-dry it, and weigh the remaining solids on a very accurate scale. Which also has the benefit of taking the non-salt ingredients into consideration (which won't even bump an EC meter's reading).

That might be a slight simplification - but only a slight one.

I so love a scientific mind!

 

[TorturedSoul]

Yeah, they're so tangy .