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

[1969gtx]

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.
My soil is pro-mix and FF, 60/40 with 10% extra perlite. I also added some alfalfa meal in the mix, one solo cup to 6 gallons of soil.

 

[1969gtx]

I just did that same slurry test with water ph at 6.3, and it came out at 5.9. Seeing this, I guess I should be setting water ph to about 6.8, to get run-off to the desired 6.3 ish?

 

[Stunned]

I tend to keep my PH lower because it always comes out higher on runoff
but then again I'm growing in coco....

 

[NOOOBIENOT]

I just did that same slurry test with water ph at 6.3, and it came out at 5.9. Seeing this, I guess I should be setting water ph to about 6.8, to get run-off to the desired 6.3 ish?

I just did that same slurry test with water ph at 6.3, and it came out at 5.9. Seeing this, I guess I should be setting water ph to about 6.8, to get run-off to the desired 6.3 ish?

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.

 

[1969gtx]

This is what led me on this runoff question. Thursday, I transplanted . I watered with plain bottled spring water. They loved it, leaves up higher than ive ever seen. This morning, I watered again, pH adjusted to 6.3. They drooped, now I see this, which looks like mag deficiency. I'm guessing i was in nute lock-out.

 

[Emilya Green]

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.

 

[Stunned]

yeah, there's truth in the above
soil is a complete mystery to me

 

[1969gtx]

Yeah, the soil is much more complex than I anticipated.
Emilya, thanks for joining. I was hoping you would. Very well written, I must say. Does that pic seem like mag deficient?
I value everyone's input, so keep the ideas coming.

 

[Emilya Green]

Yeah, the soil is much more complex than I anticipated.
Emilya, thanks for joining. I was hoping you would. Very well written, I must say. Does that pic seem like mag deficient?
I value everyone's input, so keep the ideas coming.

Hi 1969gtx, nice car by the way! Happy New Year! I do think that I see some mag deficiency, but I am more concerned about the look of the leaves overall... I suspect that you are watering too often. How do you determine that it is time to water?

 

[NOOOBIENOT]

Hello , Emilya , do you make your own soil or is it store bag bought ?I have bought probably 50 different bags of pro mix soil and all of them were very different on the ph of the product and I know it is even more different between different manufacturers , I feel that measuring run off gives a GENERAL (NOT TOTALLY ACCURATE) idea as to where your soil is actually on the 1-14 ph scale. I have had bags of soil as low as 4.5 and as high as 8.6 , so 6.3 ph of water on a soil that is 4.8 and a soil that is 8.3 gives the roots a very different environment to survive in and absorb nutes from .I am not saying I disagree with what you are saying .but what I am saying is we can send a probe to MARS but we can't accurately ph our soil W.T.F , so if measuring runoff is not the answer then what is ?Making your own soil ,you control what's in it, store bought soil is their recipe , Pro mix is made in a town called Brantford and is 15 minutes from my house and I have watched it being made, it is a large front end loader filling a hopper to a elevator to a bagging machine , then it sits in their storage building and then it sits outside at home depot for the summer and all winter on the product that isn't sold that year , I watched a guy get off his bulldozer and take a piss on the soil pile, -no lie !! to lazy to walk back to the washrooms in the office building so the quality and controls are always different from bag to bag , I am not here to bash pro mix as I am sure the manufactures are all the same .having some kind of a starting reference point is better than nothing and working to get to the sweet spot of 6.3 is the goal and then let the soil do its ranging thing is the idea , I know this to be fact as I have a 8x12x2 ft above ground outdoor planter (with pro mix in it ) that I made of 2x10x12 ft wood and some plants I put in it just wont grow in it because the ph is to high for that type of plant or the ppm of the soil are to high or low , so what is the answer . mother nature maintains the ph of the soil with the rain water and the changing of the seasons and the different microbes,decaying organic matter etc , how do you get those kinds of conditions on a indoor grow and a bag of man made mass produced soil.ranging is a good thing I agree but ranging from what starting point is the issue .

 

[NOOOBIENOT]

I have actually done slurry testing on 1- 50 lt bag of pro mix and the top of the bag is usually alkaline 7.5-8.3 where as the bottom of the same bag is more acidic 5.6 -6.8 and the ppm`s were all over the place for numbers .

 

[Emilya Green]

I have actually done slurry testing on 1- 50 lt bag of pro mix and the top of the bag is usually alkaline 7.5-8.3 where as the bottom of the same bag is more acidic 5.6 -6.8 and the ppm`s were all over the place for numbers .

I will suggest that if you are getting multiple and conflicting readings at different points in the bag of soil, that you need a larger sample size. If you go with too small of a sample, on one reading you may have some of the buffering material, on another you may have a larger percentage of peat... to get consistency, use more soil in your slurry test. With proper methodology, we can accurately measure the base pH of our soil. Yes, I agree that reports are that consistency among soil manufacturers is often times missing, and this is why I gave up and built my own soil, starting off with the highest quality soil that I could find as my base, Roots Organic 101.

 

[NOOOBIENOT]

I agree but the noobies don't thoroughly mix their soil and don't add extra ingredients to it(maybe some perlite ) they just cut open the bag and pour it in the pot ,hence they have problems .

 

[Emilya Green]

Let the buyer beware. Don't buy your soil from the open bins outside in the rain at the local hardware store. If you see someone pissing on the soil, never buy that soil... that's not that hard to figure out. Let's stay on topic though... this thread is about measuring runoff. No one has yet offered a counter to my argument that this practice in soil is an exercise in futility.

 

[1969gtx]

Happy new year everyone!
More good info, loving it, so thanks again to all that have replied. Plants are happy this morning, leaves up, but I see more mag deficiency signs, this time on the GDP clone. I forgot to mention before, I did add 1 ML of cal mag to the half gallon of water I used. This is another reason I'm leaning towards nut lock-out. Now, I can't wait for them to dry up for the next watering, this time, with the water PH'd a little higher.

Emilya, I tried to use the weight method for watering. It was a little different this time, since it's a new size container. If anything, I underwatered. I did water slowly, letting the new soil soak it up, then adding more water until I achieved some run off. This was done with a half gallon of water, which I feel wasn't enough, but I was to the point of run-off. I'm only refering to the 5 smaller plants.
Noobienot, good info. My pro-mix did smell like piss!

 

[Emilya Green]

Since you are still in veg and the primary needs of this plant are nitrogen, it is extremely hard to lock out nitrogen which is mobile across a huge swath of the pH range. If your rust spots continue to spread, just add more calmag... your dosage right now is quite timid actually... and your plant may need more. Some of our plants are simply magnesium hogs. Your last shot of the girls showed all the leaves up reaching for the sun. I no longer am concerned about your watering method, those look like some strong and healthy roots.

 

[NOOOBIENOT]

Let the buyer beware. Don't buy your soil from the open bins outside in the rain at the local hardware store. If you see someone pissing on the soil, never buy that soil... that's not that hard to figure out. Let's stay on topic though... this thread is about measuring runoff. No one has yet offered a counter to my argument that this practice in soil is an exercise in futility.

futility and insanity are of the same thing , doing the same thing over and over and expecting a different result is futility(insanity ) .Creating your own soil is a whole different thing , you know that 25lbs of soil , 2lbs of dolomite lime , 2 lbs worm casting 2lbs of green sand etc gives you a soil of a set rough ph and the ppm`s , buying a soil from a grow shop or Home Depot you have no idea what's in it (it could be half dog shit ), there fore we need some kind of gauge as to what the soil is doing I never said it was totally accurate but it will tell you if it is too alkaline or to acidic and the rough ppm and yes soil changes as the plant takes what it needs but a constant monitoring of the soil gives a rough ideas as to what is going on -I didn't say it was totally accurate, it is just some little bit of knowledge and knowledge is power and helps to make informed correct decisions as to what to do next , unfortunately this is all we have as a tool to gauge , unless you want to buy or send your soil to a lab to get some kind of a base line to work with, something is better than nothing , half empty glass or half full glass or a totally empty glass , I will always take the half full glass at least I can drink for another day .

 

[Mark Gordan Smith]

I watched a guy get off his bulldozer and take a piss on the soil pile,

There may be a vacancy for a Dozer-Driver in Brantford shortly.

 

[NOOOBIENOT]

Well I love your pic Mark but it only proves a point that every person ,plant requires a little different something in their lives .ya the company needs a drone to keep a eye on the dudes out in the yard !!

 

[Emilya Green]

futility and insanity are of the same thing , doing the same thing over and over and expecting a different result is futility(insanity ) .Creating your own soil is a whole different thing , you know that 25lbs of soil , 2lbs of dolomite lime , 2 lbs worm casting 2lbs of green sand etc gives you a soil of a set rough ph and the ppm`s , buying a soil from a grow shop or Home Depot you have no idea what's in it (it could be half dog shit ), there fore we need some kind of gauge as to what the soil is doing I never said it was totally accurate but it will tell you if it is too alkaline or to acidic and the rough ppm and yes soil changes as the plant takes what it needs but a constant monitoring of the soil gives a rough ideas as to what is going on -I didn't say it was totally accurate, it is just some little bit of knowledge and knowledge is power and helps to make informed correct decisions as to what to do next , unfortunately this is all we have as a tool to gauge , unless you want to buy or send your soil to a lab to get some kind of a base line to work with, something is better than nothing , half empty glass or half full glass or a totally empty glass , I will always take the half full glass at least I can drink for another day .

so what do you glean from your runoff measurement about your soil then and how can you give it any validity at all knowing that the numbers you get are an arbitrary (not just inaccurate) number? What sort of base line is this, if it is misleading? This is worst than nothing at all actually, it is reacting to ghosts. I see people on here all the time recommending to flush the soil, flush because it is too hot, flush because the pH is too high... but I argue they are starting off with incorrect premises and backed up by arbitrary readings and reacting to things that may or may not be there.