Greetings DGC,
I have a fulvic acid powder from NPK Industries called “Full Up”. I always heard fulvic acid is amazing for delivering nutrients into the plant. Does anyone have experience using it as a pH down? Any negative effects?
I’m currently using phosphoric acid for pH down and the plants have no issues and stink like crazy. I nail pH 6.4 and all my plants in coco-based living soil are very happy. My reservoir doesn’t have any nutrients in it, just the phosphoric acid.
Thanks!
Fulvic acid will lower the pH without any negative issues normally.
The only situation that could cause undesired results would be if your water source was alkaline enough that you’d use a bit too much acid to lower the pH and if coupled with a bunch of run off you’d be stripping your medium of goodies.
do all fulvic acid products lower ph ? and isnt there controversy on the difference between fulvic and humic acid ?
Yes. I’d assume (since I haven’t personally used every product). fulvic acid dominate products should lower the pH unless they mix them with some alkaline ingredient/s like kelp. The degree of acidity depends on a few things. Humic and fulvic acids are both considered humic substances and are chemically the same hence the debate. Fulvic acid is technically a humic acid. The difference between humic and fulvic is the size of the molecule, elemental ratios and also acidity. Both are made up of some mix of carbon, hydrogen, oxygen, nitrogen and sulfur. The carbon and oxygen ratios determine the acidity of the molecule and it’s molecular weight. Think carbon heavy and oxygen light. A lower molecular weight means more oxygen than carbon. More oxygen means higher acidity. So bottom line is fulvic acids have a lower molecular weight than humic acids, so fulvic acids are more acidic. They both come from microbes breaking down lignin. Coco is basically 2/3 cellulose and 1/3 lignin. Microbes love coco because it’s mainly cellulose (sugars). Lignin is what gives plant cells their structure like the wooden framing of a house while the cellulose would be like the drywall.
A thing of note that never gets brought up is fulvic acids are organic (carbon based) molecules that do not rely on ion exchange at the root hair tips like inorganic mineral cations and anions.
Mystro never fails to drop the knowledge! Thank you buddy.
Something I recall reading previously is that fulvic acid is stable in solution at a more wide pH range, where other humic molecules will precipitate outside of a more narrow pH range.
A few super interesting things in Mystro’s comment that I found awesome:
1: “The carbon and oxygen ratios determine the acidity of the molecule and it’s molecular weight” I had never heard this way of thinking about acidity & pH.
2: “They both come from microbes breaking down lignin.” I had no idea this was the case. How come people don’t talk about this stuff, it’s so interesting!!!!
3: “fulvic acids are organic (carbon based) molecules that do not rely on ion exchange at the root hair tips like inorganic mineral cations and anions” I think this is some powerful knowledge, and I’m thinking this would be the advantage of using fulvic acid in place of phosphoric acid.
I’m absolutely going to try out fulvic acid as a pH down, but I’ll try it in a separate smaller reservoir and only use it for one plant. Not a perfect experiment, but I might get some anecdotal evidence to start with.
****Also, my water is VERY alkaline and it takes a huge amount of phosphoric acid to get to pH 6.4. So then I WOULD be worried about it stripping nutrients from my soil. But… I don’t every water until runoff. So I might expect some nutrient burn if too much fulvic gets into my media. Possible solution is to use a combination of fulvic acid & phosphoric acid to get pH 6.4.
Cool discussion! Thanks!
Beast
I’d stay away from high doses of phosphoric acid since you say your water is hard (alkaline) which tells me it’s high in calcium. It can bind to the calcium. Humic acids are only not soluble at pH ranges less than 2. So it is still pretty soluble. It’s purpose is not to bring cations into the plant through the roots like fulvic acids can. Humic acids grab and hold these cations to prevent phosphate anions from binding them together in soil or solution. Cations and anions are also classified by magnitude. Cations like calcium, magnesium, copper, iron, manganese, zinc get grabbed by an acid to become humic/fulvic cation salts or complexes. These cations have a stronger positive charge (plus 2 magnitude) than the weaker charged cations (plus 1 magnitude) potassium and also sodium which is not essential but helpful element also grabbed up by humics and fulvics. As you can see, a whole bunch of elements are protected from phosphate anions (minus 1 or 2 magnitude depending on form of phosphate) when humic and fulvic acids have a hold on them.
‘”Humic acids grab and hold these cations to prevent phosphate anions from binding them together in soil or solution” Makes a huge amount of sense. Awesome. Definitely adding the fulvic in my garden
As a side note, even though they are called humic and fulvic acids the highest quality ones are often very alkaline (seems counter intuitive but true). Elevation organics Humic Acid Test is alkaline with a pH above 10. It is sourced only from leonardite and when used with the rest of the Elevation Organics line is actually used as a pH up. The process of acidifying a solution of humate causes the humic acid to precipitate out into solution (turn solid) so if you have a bottle of humic acid and want it to be in a liquid form it is my understanding that the solution must be alkaline or you would have a bottle of “soild humic acid” or get a powder like you would find in BioAg Ful-Humix as the result of acidifying the solution and collecting the solid “humic acid” or “humin”. Fulvic Acid on the other hand is soluble down to a very acidic pH of 2 which allows for the black and dark colored humin and humic acid to be extracted leaving a high quality golden colored fulvic acid. I am trying to remember all this from previous soil science classes (and welcome corrections and more conversation) and discussions with the BioAg folks who have all variations of the humic and fulvic products. So don’t be suprised if you have a bottle of humic acid (the dark stuff) and it is actually alkaline and raises your pH. I do not disagree with any of the previous information posted just that there is more to the story and that humic “acid” is in fact not acidic but alkaline.
Over very long periods of time lignin collects and compresses in the soil into a soft sedimentary rock called lignite. Lignite is put through an oxidation process to become leonardite which is highly soluble in an alkaline pH like 10 to extract the acids. Fulvic acids are soluble at all pH ranges and humic acids only lose solubility below a pH of 2. I was speaking about the acidity of the acid’s themselves and not the pH of a companies liquid bottled formula. That can be buffered to any pH above 2 to keep the acids soluble.
Thanks Professor and Mystro. Learning more every time we converse!