pH & the Organic Enviornment

[B.C.]

In other words it's redundant, because it fightin against itself.

 

[B.C.]

hhmmm...

hhmmm...

I prolly should read Suby's link before postin this,but doesn't bio activity cause arise in ph.Like when ya bubble tea,the ph goes through the roof an then comes back down.Also usein FoxFarm,soil the ph starts out low 6.3-6.4 (it varies alil),but by the time I'm done with it,it's around 7.I know the water may play a part in on this,cuz I jus use tap water witha neutral ph of 7.But that doesn't explain the teas goin so high. Any comments on this? BC

 

[quadracer]

I found some interesting information:


How Important are Specific Growing Medium pH's for Foliage Plants?

C.A. Conover, Ph.D.*

University of Florida/IFAS
Central Florida Research and Education Center
Research Report RH-96-2

During foliage plant production, growers often monitor certain factors affecting plant growth in order to produce high quality crops. One factor indirectly affecting plant growth is pH of the growing medium. A pH of 7 is considered neutral, a lower pH is acidic and a pH above 7 is alkaline; but producers of container grown plants need to understand just what these numbers represent and how the pH of the growing medium can indirectly influence foliage plant growth. We know that pH is defined as the measurement of the negative log of the hydrogen ion [H+] or hydroxyl ion [OH-] concentration. If we compared the pH of two potting mixes and one had a pH of 4.5 and the other a pH of 6.5, we would know that the medium with the lower pH contained more [H+]'s.

Since pH is a logarithmic scale, the difference in the number of [H+]'s between soils with pH's of 4.5 and 5.5 is much greater (one hundred times greater) than the difference in the number of [H+]'s between soils with pH's of 5.5 and 6.5. Therefore, many more [H+]'s are needed to lower the pH from 5.5 to 4.5 than are needed when lowering pH from 6.5 to 5.5.

Most growers who notice a decrease in medium pH of container grown foliage plants may

wonder what causes this and why it can sometimes happen so rapidly. The main cause of decreasing pH of the "soilless" growing media favored by the foliage plant industry is related to the fact that these media are organic in nature. Decomposition of organic matter results in the formation of both organic and inorganic acids. These acids cause the basic ingredients of the potting medium, such as calcium, to dissolve and eventually leach out, which then results in lowered growing medium pH. Fungi, which utilize the organic components (carbon) of potting medium as their food source, also significantly contribute to acid formation.

Often, another major source of acids are the fertilizers applied for plant growth, with different nutrient sources responsible for eventually causing high or low acidity. For example, one 20-20-20 fertilizer needs 597 lbs of CaC03/ton to neutralize its acidity, while a 20-7-9, a fertilizer with different nutrient sources, requires only 273 lbs. Most fertilizers utilized in the foliage industry are acid forming, and the higher the fertilizer application rate used, the more acidity created.

Although most plants will grow within a wide pH range, 3.5 to 8.0, for many years the suggested range of pH values for growth of good quality foliage plants was 5.5 to 6.5. This recommendation originated back when most ornamental plants were grown in mineral or organic soils or soil-containing mixtures. In soils, this is the pH range where nutrients required for foliage plant growth, such as nitrogen, phosphorus, potassium, sulfur, calcium and magnesium, are most available for plant uptake. In addition, within this pH range, potentially harmful micronutrients these soils may contain, (iron, manganese and zinc, as well as the element aluminum) are mostly insoluble or only slowly become soluble and, therefore, less available to plants. As growing medium pH decreases, the compounds containing these micronutrients dissolve and basic components such as calcium are leached, so that the amount of aluminum and the micronutrients iron, manganese and zinc available to plants is greatly increased. However, soil is rarely a component of the various types of modern media used to produce foliage plants. Aluminum is not a significant component of artificial growing media and additions of iron, manganese and zinc are specifically controlled when artificial media are produced. The chance of a micronutrient toxicity problem developing as pH decreases is unlikely for plants grown in a good quality artificial growing medium. When micronutrient products are applied to foliage crops at the rates recommended by manufacturers, micronutrient levels in the medium are sufficient for healthy plant growth, but below levels needed to create toxicity problems.

We have conducted a large number of experiments over the years on various aspects of growing medium pH. For many years, we have suggested that dolomite be incorporated into peat and peat-bark based potting mixes before use, at the rate of 7 lbs/yd3, to help adjust and maintain the growing medium pH at the recommended level and to provide calcium and magnesium needed for healthy growth. None of the research we have conducted indicates these dolomite incorporation rates should be changed, especially in view of the fact that our research has shown that it is very difficult to increase pH of media already being used to grow a foliage crop without damaging plants.

Use of higher dolomite incorporation rates is widespread in the industry, but we feel that this may cause more problems than it helps. Further additions of dolomite produce little change in pH but do create a much higher base saturation of the medium, which often results in decreased availability of necessary micronutrients.

When most foliage crops were grown in soil, the recommended pH range was 5.5 to 6.5. This recommendation is still a valid recommendation for any producers still using soil to produce foliage plants. As the industry shifted from use of soil to various artificial media, use of artificial media also increased at our research facilities. For the past twenty years, most plants used in our research were grown in artificial media. To reflect this change we recommended a pH range of 5.0 to 6.5 as best for foliage plants (Conover and Poole, 1990). However, during research on nutrition of foliage plants, pH has often been observed to decrease over time. Often, at the end of a crop production schedule or termination of the experiment, pH would be lower than 5.0. Media pH's as low as 2.9 have been observed, and a range of 3.5 to 4.5 has not been uncommon and has been associated with foliage plant crops of high quality. In examining our data, we have not been able to associate any problems with pH's as low as 3.5 to 4.5 at the end of the crop cycle, and therefore we are revising our suggested pH range for foliage plants from 5.0 to 6.5 to a new range of 4.0 to 6.5.

We have previously published information on suggested levels of dolomite for use in artificial media as well as ways to raise pH of media containing growing plants. The data found in these publications on dolomite levels, as well as ways to safely raise pH, if desired, are still valid. In addition, in two recent reports we have made available results of new research on adjusting pH and effects of using different dolomite sources. The primary purpose of this report is to inform growers that we have not observed plant problems due to a pH range of as low as 3.5 to 4.5 occurring at the end of the crop cycle on foliage plants used in our research, when plants were grown in various types of peat, bark or peat-bark based artificial media. We feel that growers using such media need to reconsider their attempts to adjust pH's below 5.0 but above 3.5, especially if these efforts might negatively affect marketability of the foliage crop.

 

[gromer]

I think I understand now.I only use prolly about what you use or less for lime.And I totally know what you mean about the r/o water and the ph being so easily changed.Example my water out the tap is 8.2 it takes 20ml per gallon of fulvic to bring it down to 6.3.After the r/o filter it takes less than 5 mls.Ive had my water that comes from a well analyzed and I know that most of the 120ppm is cal and mag as well.So I have been thinking of just going with the tap all together and stop adding cal and mag in the form of lime.I have noticed cal and mag def in early flower since the switch to r/o.So I figure its a double negative affect by stripping out the cal and mag and then just putting back in.I guess I thought my water was real bad turns out its good stuff.Im just gonna use the r/o for foliars and brewing small batches of tea.
I also have noticed a gradual rise in my soil ph over the course of a run.So what your saying is cut out the lime alltogether.Ph the tap water and the soils ph should stay in range better?

Also what are these soil ph testers I hear of are they the pointy ended triangular dealys with like the big round watch face.Ive seen em at my hydro store looked better than the probe style.Are they any good anybody got one that likes it?I have two probe ones and they both kinda suck.I get better reading with the rapitest vial kits.Thanxx Suby for all this input in helping me figure this out.Its one thing that Ive been working on getting figured out.I just know that when I started adjusting my water my results got way better thats the only reason Im saying that Ph in organics is important.I know its not crittical like hydro but I still think it matters to a degree.Thanxx man,Gromer.

 

[HeadyPete]

Hi Gromer,

Yes, you will see a gradually rise from the lime. It is slow acting. Cut out the lime, use the tap water for awhile (bubble it for a couple days if it is chlorinated) and look for signs of deficiency. Some strains are pigs for cal/mag, and each one will tell you. Look for lightening of the leaves, while veins stay dark green (mag def), and/or brown crispy spots on leaf face and/or edges (cal def). If these start, add CalMag. I use 5 ml/4L currently.
If calmag is not organic enough for you, go back to the lime, and test and counter the ph rise every watering.

IMHO, ph is most critical to plant health, hydro, soil or whatever. PH needs to be optimum, or certain nutrients will become unavailable to the plants, and deficiencies will develop. The only thing that can correct that is proper ph. Most plant problems around here originated with a ph problem, and lack of testing/adjusting. I have and recommend a digital ph pen. I got a Milwaukee PH40 for $70, much more economical than the high end pens, but still accurate. The soil probes are poor, and too inaccurate. You need to see your ph to the first decimal, as in 6.8, not 6ish. Ph is reverse logarithmic, as in 6 is 10 times more base than 5, and 7 is 100 times more base than 5. Now you can understand why you need to be accurate.

I measure water, water after nutes, water after adjustment, and plant runoff, to be sure.

Interesting about the fulvic acid as a ph down. I use phosphoric acid (20%), but it is not organic (formed from inorganic mineral), it is non toxic, but detrimental to human bone health and an ingredient in Coca Cola, and I like the beneficial qualities of the fulvic as well, as it's organic. I think my next trip to the hydro store I will get some fulvic and stop the phosphoric. Thanks!

 

[gromer]

Im with you on all that pete the pens the measuring ,I do all that.I just know they make a nicer more accurate tester than the probes for soil and was wondering if anyone could tellme more about em.Like maybe the proper name even.I know ive seen em.Just wanna hear somone say that they are decent.I totally know what you mean about the to the decimal thing if you go back in the thread thats pretty much the whole point I was making.Peace,Gromerr Pott!!

 

[MrDank]

2 TBSP Dolomitic Lime per gallon of soil

With a digital ph pen, make sure anything you are watering into your soil is around 6.0-6.2

You can use the ph pen to test the ph of your runoff. You want your run off to be between 6.5 and 7. If you have the lime in your soil and your runoff is lower than 6.3 then something is wrong and you probably want to bump the ph of your water up a little. For the most part as long as everything you are doing to your plant ph wise is in the 6-7 range, you will be ok. Even at 11 weeks of bloom I am still getting a ph runoff of 6.5-7

PH is VERY important to the plant

 

[gromer]

Thanxx Mr.Dank but did you actually READ any of this thread or just the last post?Awesome post quadracer!!!Good thread we got goin here!!Lots o good info!!!

 

[Suby]

Agreed great post Quadman,

We have conducted a large number of experiments over the years on various aspects of growing medium pH. For many years, we have suggested that dolomite be incorporated into peat and peat-bark based potting mixes before use, at the rate of 7 lbs/yd3, to help adjust and maintain the growing medium pH at the recommended level and to provide calcium and magnesium needed for healthy growth. None of the research we have conducted indicates these dolomite incorporation rates should be changed, especially in view of the fact that our research has shown that it is very difficult to increase pH of media already being used to grow a foliage crop without damaging plants.

Use of higher dolomite incorporation rates is widespread in the industry, but we feel that this may cause more problems than it helps. Further additions of dolomite produce little change in pH but do create a much higher base saturation of the medium, which often results in decreased availability of necessary micronutrients.

This post says alot about how balance is necessary in the whole ph discussion.
Notice how he mentions that too much dolomite can do more damage than good, well this has to do with cation exchange and how positive and negative elements are going to determine balance.
For example having loads of dolomite mean that cations like Mg+2 and Ca+2 are saturating the mix, they will compete with say K+ and other postively charged particled for uptake around the rootzone, seing as ALOT more Ca and MG are present by default they outnumber thus outcompete other similarly charged elements.
There are ALOT more things going on here but essentially this is how I have come to understand it.
This is where organic buffering comes into play, you want a balance in elements that is why NPK is important to monitor and change according to your plants growth stage and why untimately a lower ph in flowering is normal and by the end so many crucial positive ions are out of suspension.

I hope that is relatively clear..ask ?'s if it's not please.

Suby

 

[Toucha Death]

just gonna throw this in there...i know ive heard testing ph of organics clogs your pens electrode...anyone heard of this? i was thinking about buying a pen and im pretty sure im gonna buy one that has a replacable electrode... i wonder if i can get a ph/ppm meter with replacable electrode???anyone??

 

[HeadyPete]

I rinse mine (Milwaukee PH 40) with plain water and then the 7.0 buffer solution for storage, so far so good...

Yes, most if not all pens have replaceable probes.

 

[Tom Hill]

A soil farmer can quickly provide a hostile environment for beneficial bacteria by disregarding proper pH monitoring. One example would be that nitrogen fixing bacteria (the little guys that convert nitrogen into nitrates) do not survive at a pH of less than about 5.8. Skating through a 3 month cycle disregarding such things is to be expected, however, the long term soil farmer is well advised to pay closer attention.

 

[gromer]

Wow cool Mr.Tom Hill of all people pops up from no where and cements exactly everything I was saying.See folks Im not crazy after all!!!Thanxx Tom!!

 

[Amber Trich]

If you used dolomite lime at even a low rate with starting water ph of 8.2 then I can guarantee lime will create more problems than solutions.
If your water is 7 and under, then dolomite will help you out in buffering.
Your starting ph is so high that when combined with the lime your soil will easily fall out of a controlled ph zone, that's why I stress the importance of knowing your starting water's ph and ppms.

Jiggy has the same problem, he used the lime and had problems because of this combo of high ph water and lime on top of it.

You could probably skip the lime entirely and just rely on the peat ph being lower and feeding with tea ingredients that will lower ph in and of themselves like guano, fish emulsions, humic and fulvic acids are a great choice, as a bonus the humic and fulvics will further make nutes available over a wider ph span, which from what I am reading is what you are doing

WOW
I feel like this should have been made clearer in the first place.
I have been carefully following suggestions with very poor results and now I see why.
Everyone in my area has water with a ph over 7.
OOOPS
Thats why its important to keep learning, keep reading!

 

[B.C.]

So why is my soil ph around 7 when I'm at the end of flower? I don't use lime at all.And if bioactivy doesn't cause a rise in ph,why does the ph of the teas go so high before commin back down.Seems like the harder ya bubble it (more air),the more it goes up too ? is this not from the bioactivity running rampent from all the air? I haven't made teas or checked ph's of anything fer years now and I have no problems what so ever.But back when I was first lerning about this I checked EVERTHING all the time,and this is what it boiled down to.So if someone can enlighten me I"m all ears.Thanks.Take care...BC

 

[Suby]

Amber Trich I'm glad that cleared things up for you, I'm sure there are other organic growers having lockout issues due to their water source, poor water sources are difficult to gauge in reaction to a healthy soil mix.

I find bubbling brings ph up all the time, during flowering plants use alot of positive charged ions like K and P which once depleted from the soil can sway the soil's ph, it's just a theory. The method of measuring soil ph has to be flawless though, I see alot of useless ph probes out there, usually using RO water in equal volume of soil mixed and strained then ph pen tested works best.

Besides even after bubbling EJ products the ph goes down when bubbled but swings back up a bit once it's left to stand, I have yet to test my bacterial teas.

S

 

[B.C.]

Thanks Suby

Thanks Suby

I am assuming the latter half of yer post was directed towards me (?).When I tested the soil it was always from run off caught ina cup.I would let any solids sink ta the bottom,after a min er two and test it with hanna ph pen.Should of been accurate,ya think? As far as earth juice goes the first and last (only) bottle of grow I bought was fermented,only after not bein able ta keep the ph stable at ALL(this was ina hydro setup), did I realize this.Since then I guess they ph it way lower ta keep it from eatin itself up on the store shelf.So the guy at the hydro store says,(which btw knew the batch I got was bad).All of it is too much of pain in the ass fer me tho,and that's not ta mention the stink! Imo a five part nute system that yer supposed ta bubble fer 24 hours and stinks ta high heaven is not necessary ta grow good bud,but to each their own,by all means.Well....thanks anyway.Take care...BC

 

[Tom Hill]

Removing lime from the farmers hand is difficult because the regions where farming has occurred throughout history are often soils with a leached base low in pH due to high amounts of rainfall. In my opinion, following the recommendations for liming around here may be ill-advised & most of us would be better off omitting it. Replacing the lime recommendations with gypsum would probably be a wiser move concerning the vast majority of us.

 

[Suby]

Hey BC,

sry bout that, yep the 2nd half was for you.
I find measuring runoff innacurate because you might be flushing out built up nutrients or salts in the bottom of the container but they do give you an idea of what soil ph is close to.
EJ is not my favorite organic line, not by far but some have great results, it's a fussy product and can go bad real fast and yes far too many products to pull it all together.
I don't think they are bad just that they have a learning curve of sorts.

TH

I've tried them all except maybe oyster shell and dolomite is the best, it will make for alot less carbonates in your soil and has both Mg and Ca as opposed to other limes

S

 

[gromer]

Hey Suby you mention that EJ can go bad real fast.I got a brand new bottle of Catylyst and it smells like kinda alcoholly kinda messes with your nose and brings tears to your eyes is this normal?The bottle of bloom I got smells almost normal with like a hint of what I already described do you think they are off.I just went through this whole thing with that store I got em from cus Ive had alotta stuff be off .Got a maetanaturals grow that would curl your nostril hairs and the bloom was so settled I had to put a mixing spoon down in there and swirl it around and break it up.
I called them on it and this is after returning alotta AN stuff there already which is money back guarunteed and they had to do it.So they flipped about the Metanaturals and basically almost kicked me out.So you see I really wanna have my ducks in a row with the Earth Juice cus if not it could mean being forced to do everything mail order which would suck.Alot of the bottles on the same shelf were collapsed but I tried to be optomistic cus at the price I really wanted this stuff to be good.Seems so far the only two companies Ive had good luck with are Advanced and Botainaicare and that is only through mail order that Ive had every bottle be good.Fox Farm although not my fave has always seemed to have a quality product as well. In that the nutes havent fallen outa suspension organics settled etc..etc.Man after shopping around alotta different companies I can see now why alotta people like their products.Well hate to bother you with such a post but seems you may be the man to ask on this one.Thanxx in adavace.Peace Gromerr Pott!!