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Baking Soda and Vinegar for pH Adjustment???

Discussion in 'Organic Growing' started by jakrustle, Sep 19, 2010.

  1. I have been addressing the adjustment of pH by telling people that Baking Soda and Vinegar are two good alternatives for Up and Down. However, after talking to Ryan at BioAg and doing a lot of reading on the internet, I now believe the soundest advice is to stay away from both of these for pH adjustment. I imagine limited usage may not be critical, but sounds like the regular or extensive use of it can cause issues.

    You might read the article below to get the best explanation.

    Baking Soda and Vinegar for Hydroponic Nutrient pH Control

    by Michael E. Basham
    (Virginia) ​
    I've read that vinegar can be used to lower pH levels in a hydroponic nutrient solution, and baking soda can be used to raise them. do you recommend this practice, and if so can you tell me the amounts of each to use to raise and lower the pH level in .1 increments?

    Answer: Michael- It is true that baking soda can raise pH, but I do not recommend using it. Chemically, baking soda is Sodium Bicarbonate. High levels of sodium are like trying to grow plants in salted soil. In addition to that, the presence of Sodium compounds will prevent the plants from taking up Calcium.....which will cause all kinds of problems with nutrient deficiencies (Nitrogen is a mobile nutrient, but is only mobile to the plant in the presence of Calcium. Other nutrients will only be taken up by the plants along side Calcium).

    You're really testing me on my chemistry today, lol....

    Vinegar's chemical composition is CH3COOH....it is just a bunch of Carbon and Hydrogen and Oxygen. On it's face, none of these would interfere with nutrient uptake. However, vinegar is only a weak acid, which means you may need quite a bit of it in order to keep your pH level correct. Once you begin using more substantial quantities of vinegar in your nutrient reservoir, it may not be so cost effective anymore.

    Also, even though the Carbon and Hydrogen may not affect nutrient uptake, they still add to the total TDS (or EC) of the nutrient solution....which means the more you use, the fewer nutrients you can legitimately have suspended in your nutrient solution without burning your plants. This is why commercially available pH down is made of Phosphate compounds....they not only bring the pH down, but are also available to the plants as usable nutrients. This is not the case with vinegar.

    In reality, I don't know for sure what would happen if you used vinegar to control your hydroponic nutrient solution pH. However, I have enough concerns about it that I would not try it myself (at least not on a big scale, or on an important plant or crop). If you do decide to try it experimentally, be sure to let me know how it turns out for you....I am curious to know for sure.

    The best way to avoid the expense of pH down (and to a lesser degree, pH up) is to choose your hydroponic nutrients well. B.C. Nutrients mix up at the right pH, and the pH changes very little over time. The same is true with Canna Bio. Other nutrients require a LOT of pH adjustment, like Earth Juice. Hope this helps Michael, and Happy Growing!
  2. Either can be used in emergencies, but I always tell people it's worth spending a few dollars on proper pH up and pH down. It's not expensive, it goes a long way, and it doesn't mess up your chemistry.
  3. Not only that, which is absolute solid advice, but also careful selection of your N sources will help you with managing soil pH as well. You have to know whether your N is an ammonical or urea based source (acidic), which will tend to drive pH down over time, or a nitrate source (base) which will tend to drive pH up over time. Not to mention the other "thing" (CeC).

    Know the sources from which the nutrients are derived and there will be much to learn there. Otherwise, as OSG put it simply, use the professional products for longer acting results. With doing so, also make sure you understand their source (phosphoric, sulphuric, etc) because these acids will also impact your N-P-K balance and nutrient availability.

    Fun stuff eh?
  4. Possum and Oldskool, thanks for the additional info.

    Possum, how do the meals such as alfalfa, bone, blood, kelp, etc. fit into those two groups you mentioned. Or are there others?

    I imagine the Urea based ferts would be things like guanos (?). How about the alfalfa, bone, blood, crab, fish, etc?


  5. Jak, i thought that you were using organic homemade soil mix? For me, I think that you don't need adjusters... nor a ph pen. I used mine for years, constantly. On water, feed, nutes, soil suspended in water and on anything that i could stick it in. Now i grow in soil, not just crap dirt, but amended soil stocked with lots and lots of microbes of various sorts and they like whatever ph the water is, and they use it to give the plant the nutrients that it needs. I haven't used my ph pen in a lot of months now. You don't make a susupension or a tea and then ph it, you kill off the stuff growing in it, let them figure out what ph it should be. This is a soil based approach though, not hydroponics.
  6. #6 Possuum, Sep 20, 2010
    Last edited by a moderator: Sep 20, 2010

    Ya know jak, the short answer is, "it's complicated". But without getting to far off into the weeds with an answer, a short search produced the following for me but unfortunately I didn't copy the link where I found the answer (a .edu domain). Subject to review, verficiation, and critique (of the many, many variables that can influence the following....)

    Alfalfa meal – neutral
    Bone meal – alkaline
    Blood meal – acidic
    Cottonseed meal – acidic (I wouldn't use much! Very acidic)
    Glutton meal (I wouldn't use it at all for many reasons)
    Fish meal – acidic (some types)
    Hoof/horn meal – alkaline (most)
    Kelp – neutral

    Quite frankly, one could grow a harvest crop using a good base soil mix ammended only with EWC, alfalfa, and kelp, and add nothing but clean water and two/three AACT's during the grow. In 90 - 120 days you'd be a happy mofo :) .

    Of all the seed meals alfalfa is clearly the best choice for nutrient value and if only going to use one seed meal use it. Pest control aside, alfalfa... it's the best for nutrient value seed meal. (did I already say that?) :confused:
  7. Skunk, you know how thick I am, even with all I have learned from you guys. I have been pH'ing my water all along. Even when I use the seaweed extract and the Dyna Gro Protekt, which really raises the pH.

    When I used the TM 7 (only one time) I had pH'ed the water, but after I put the Humic Acid, 1/4 tsp/gal H2O, it was in a good range.

    So, Skunk, you are telling me don't bother pHing my water now that I am amending it with these organics?? I love the idea and the one less hassle. Let me know.

    Possum, thanks for the advice. I love the idea of the simplified soil with the teas throughout. I can't wait until my next grow. I am going to go with Sphagnum Peat, perlite, EWC, alfalfa meal and a couple of other meals and see how it goes. I am really complicating things and have to learn how to listen to your advice better.

    Peace from the far north!!

  8. jak- this is a post i added to another fellas thread a while back, for the sake of time i've just pasted it here for you.

    "here's a tip i got a while back and it's totally changed how i grow. go all organic and use good water (filtered, r/o'd, distilled, etc...) basically any water with a low ppm, and you won't need to worry about your ph again, ever... it may be hard to believe but it's true, a good organic soil with a high cec (cation exchange capacity) will actually buffer the ph so that your plant can pull out and use nutrients when it wants. no more worries about washing your nutes out when you water and no more chasing that damn ph all over the place!

    also if you're using less than quality soil with a low cec, and ph'ing the runoff, keep in mind that your reading will fluctuate as more nutes are being leached out of the soil when you water. it takes more work but a more accurate ph reading can be done by a slurry test. mix distilled(or known ph) h20 with a sample of your soil, stir it up and let it sit for 5 minutes, then stick your meter in there. you'll get a more accurate more consistent reading, though if you take my first tip you won't have to worry about the second."

    build yourself a rich diverse soil, high in organic matter and then kiss those ph issues goodbye brother!
  9. btc, excellent advice. i am going to work on that. I got the organic diversity, but I seem to keep stumbling here and there getting to right "make up". The thing I want to understand is, how available is the alfalfa meal, kelp meal, bone meal and other amendments I put in my soils. I understand that when I mix the soil up, add my amendments, put the plants in the next day, the amendments won't be available. But, sometime down the road they will. I really want to understand when they will be there so the amendments are most available/beneficial to the plants as they veg and flower.

    If you mix your soil and put in these amendments and maybe water and beneficial tea, do you wait a week, a month, two months before you put your plants in?

    Thanks for helping me out, btc.

  10. JaK

    The reason for that is best explained with this humic acid elemental graphic:


    Humic acids are thought to be complex aromatic macromolecules with amino acids, amino sugars, peptides, aliphatic compounds involved in linkages between the aromatic groups. The hypothetical structure for humic acid, shown in figure, contains free and bound phenolic OH groups, quinone structures, nitrogen and oxygen as bridge units and COOH groups variously placed on aromatic rings.

    Here is fulvic acid:


    Here is how it plays out in a pure humic acid like the one that you're using from BioAg


    Properties of Humic Substances

    Humic Acids - the fraction of humic substances that is not soluble in water under acidic conditions (pH < 2) but is soluble at higher pH values. They can be extracted from soil by various reagents and which is insoluble in dilute acid. Humic acids are the major extractable component of soil humic substances. They are dark brown to black in color.

    Fulvic Acids - the fraction of humic substances that is soluble in water under all pH conditions. They remains in solution after removal of humic acid by acidification. Fulvic acids are light yellow to yellow-brown in color.

    Humin - the fraction of humic substances that is not soluble in water at any pH value and in alkali. Humins are black in color.

    Guess which one 'Leonardite' falls into - LOL

    At any rate, humic acids perform a completely different function than do fulvic acids. As you can see from the humic acid graphic, it is a huge entity with huge number of exchange sites - primarlily carbon (C), oxygen (O) and hydrogen (H) - the 'Cation exchange Capacity' of a soil.

    Hydrogen is always plentiful (water is H20) and the plant roots exude hydrogen to exchange with Calcium, Magnesium, Potassium, Phosphorus and many other elements at the cation exchange sites. Hydrogen is a base acid and if it is floating around and not attached to clay or a humus atom, it will result in an acidic coil.

    Specifically calcium, magnesium, potassium and sodium are base alkaline elements which is why some farmers apply calcium (alkaline base) to an acidic soil to raise the soil's pH.

    Fulvic acid is much smaller in structure - small enough to enter the capillary system of a plant and can carry cations along for the ride - that's a good thing.

    Where the problem comes in with an over application of pure humic acids is that they contain 20% fulvic acid. Fulvic acid (along with liquid silica) are chelating agents - also a good thing. But in high doses the liquid silica and fulvic acids also begin to chelate the other acidic base cation - aluminum. Aluminum is almost always bonded with silica and stays stable until it's freed from the bond and now you have much bigger problems than pH - aluminum will definitely do a number on your plants.

    Moral of the story is this - only apply the BioAg TM-7 product about every 10 days and only the amount recommended on the label. Contact Ryan for a more complete level of information but this is the down and dirty version.



  11. Hey Everyone --

    YES... What Oldskoolgrower said!! I agree full on!! If you are in an emergency use what you have available to you to fix your situation.... otherwise get the right stuff to do the job correctly!

    Kisses -
    Hott ;)

  12. You could make yourself a nice compost somewhere. Mine is indoors, basement, in a 'compospin'. With some thick earthy live humic composty stuff in your soil, you WON'T need to worry about the additions working, cuz the micro life with eat them up and poop them out and the plants will thrive really quick-like. I use horrible Ca heavy glacial water, our local supply, that they chlorinate, blek, and i just bubble it for 24 hours and use it anyhow, used to bubble and add PH down. I do not ph anything, ever, not for months now... because it SUCKED. I hated PH'ing everything, and seeing the 'bounce' in the bucket; if you bubble someting the ph climbs, chemistry of oxygenation. Always had to spend the time to PH the water in my airation buckets, over and over, because the oxygention of the remainder changed the PH back up. Pain in the ass. First time someone here said to put it away i did just that. You need the compost or vermi to make it all work tightly though. At least i think so. Good compost, good soil, good plants and all that.
  13. LD, thanks for the explanation on the Humic and Fulvic acids. Some complex stuff, but I thinkI got the gyst of it. I will tell you that putting a 1/4 tsp of BioAg's TM-7 in a gallon of water - after about 5 minutes that water is very dark.

    I only put one treatment (1/4 tsp/gal) on my plants so far, right after going into flowering, and planned on another when I get back home. So it will be about 2-3 weeks between Humic teas.

    I wanted to go ahead and put on the TM-7 again along with with a 1/4 tsp of seaweed extract and a 1/4 tsp of the Protekt. I am still using the Growmore (cold pressed) Seaweed Extract, but am going to get the Acadian Product from KIS. It looks like an equally quality product as compared to the TM-7. The Acadian people told me they have a retail vendor in the Phoenix area that has their products, but they do large scale sales, so I don't know yet that they will sell me smaller quantities.

    ps: I gotta look up some more info on Leonardite so I answer your question correctly. I don't want to embarass myself by answering it wrong.lol.

  14. LD, alright after some reading I want to embarass myself and say that Leonardite falls into the Humic Acid category??


    Soil conditioner
    It is used to condition soils either by applying it directly to the land, or by providing a source of humic acid for application.

    Remediation of polluted soils
    Leonardite can be added directly to soils to reduce the take-up of metals by plants in contaminated ground, particularly when combined with compost.
  15. #15 jakrustle, Sep 20, 2010
    Last edited by a moderator: Sep 20, 2010
    LD, a little more on Leonardite. Really seeing the relationship here by doing a little more research.

    What is Leonardite?
    Leonardite is a low rank coal derived from terrestrial plant matter. Leonard Dave of the University of North Dakota discovered it in 1919. Leonardite is found in North Dakota, Utah and New Mexico. It is found as outcropping of lignite deposits, usually very close to the surface.

    There are two theories on the origin of Leonardite. The first one is that it is an oxidized lignite. Compared to Lignite it has about 30-35% of oxygen whereas Lignite has about 25-30%. The second theory is that it is predominately Humic acid leached from topsoil by alkaline waters and subsequently precipitated into subsurface soil strata. (Humic acid is a form of organic plant matter).

    Leonardite Characterization:
    Humic Matter: Humic matter is complex organic molecules formed by the breakdown of organic matter. Humic matter is a class of compounds with variable structure, functionalities and reactivities. Leonardite typically contains greater than 85% Humic acid.

    Humic Matter Characterization:
    Three types of organics are identified in Leonardite. They are

    1)Fulvic Acid
    3)Humic Acid

    It is important to note that Leonardite has less than 7% of Fulvic acid and greater than 85% Humic Acid.
  16. #16 btc2112, Sep 20, 2010
    Last edited by a moderator: Sep 20, 2010
    Jak-I know exactly where you're coming from brother. When I first started mixing my soils I was overwhelmed by the whole process and was fairly certain it couldn't get any more complicated. "Am I going to starve my plants? Fry them? What happens if my girls develop deficiencies?" etc. etc. etc...

    Firstly, from my humble experience, the only macro that you're ever really likely to run into issues with not being available is nitrogen. N is the nutrient that is the most dynamic of the "big three". Standard coefficients for P and K are fairly consistent because these nutrients have minimal loss potential with volatilization or leaching (as compared to N), and they remain relatively stable in the soil. Also, and I'm sure that LD has previously said this before, but N can also become locked out or tied up if your soil mixture is still "green" or actively composting. That's why we're after properly composted material, it's goodies are more readily available for our gals, for both short and long term. If you've added quality, single ingredient organic amendments that were made for organic farming (i.e.down2earth, eb stone, dr. earth's, etc etc.) and a good humus/ewc or both, you'll have no worries brother and your ladies will take care of the rest.

    The best advice that I can give you is to try not to over think it or make it more complicated than it really is. Now don't get wrong, the things we're still learning about what really goes on in a healthy, organic soil are mind boggling. What I realized one day though is that I only needed a functioning level of that knowledge in order to give my plants what they needed to do their thing. With that base level of know-how I have been able to totally revolutionize how I do things in the garden while still learning in depth details about the more complicated parts and processes.

    1 week cook time, 2, 3, 5??? I used 'em all, and all plants not only survived but after a few weeks you couldn't tell the difference, health-wise between any of them. I'd say just do it, you seem to have a pretty good grip on what's going on down there so grab a clone or seed and "sacrifice" it to the ganja gods. Chances are you're going to be pleasantly surprised by how things turn out and how little "work" you actually have to do.:cool:

    Good luck and happy growing:smoke:
  17. Bingo!

    Real PHA (pure humic acid) contains 20% fulvic acid. The best humate is one that is high in biological activity, fulvic/humic acids, silicic acids and also high in oxygen in the phenolic and quinoid groups. Humic acids function best in the low weight fraction (fulvic) on the cellular level.

    Molecular weight is very important with the high oxygen types usually falling into the low weight (smaller sized molecules) category and thus more biologically active since only low weight molecules are utilized by beneficial organisims, enter cell membranes more efficiently, create greater permeability for the flow of nutrition into the cell and adsorption of excess heavy metals for removal from the cell.

    In agriculture, stimulation of each cell produces more energy from the plant and higher yield. The process starts with soil microbes, then plant root cells and eventually the entire plant. You can also do this by foliar spraying soluble fulvic acids and adding a humic solution to the soil at planting.

    Cellular stimulation at all levels is how it works.

    Ryan Z. at BioAg wrote 'The Real Dirt on Humic Substances' which you should find helpful since you've talked with him on the phone and know his educational background.


  18. LD, thanks for the confirmation on my answer. this is getting kind of scary as I am really starting to understand this stuff some more and know what I can do to aid my plants. I will have to wait to get home to read that article. My companies system seems to want to firewall that article.

    btc, thanks for the info and for giving me some confidence. you are right, there is a little anxiety in the beginning. Does make it more exciting though. things will get better.

    Peace fellow growers.

  19. Just always remember that it's only a plant. If something goes wrong you can grow more. No reason to be nervous :)
  20. oldskool, yeah, I know, but damn you get attached to them. I have a hard time when they are suffering and when I have to cull the males. All that beautiful growth and I gotta get rid of it. With every dead or dying leaf I think about what I could have done to avoid it, but it gets easier every day.

    thanks for helping me to keep it real. What I have to do is grow more plants, then when one gets a little unhealthy I got plenty of back up!!


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