Citric Acid

lakesidegrower said:

My two cents… my well water is about 7.2 and 220ppm full of CaCO3 as well. I was having all kinds of def, lock out and pH issues showing up in my last run since using only well water. It got worse over time and it was only when I flushed, started using rain water and pHing my water to get things back on track. In fact, I think things are still balancing out. Running no-till, 3rd run. Picking up a Bluelabs pH soil pen was a huge help.

I think what was happening for me wastwo issues: too much N and an accumulation of CaCO3 over time in my pots, given there’s never any runoff.That was causing antagonism of Mg and K and I believe was also contributing to what I found to be an average soil pH of around 7.5 when I first checked. Have been using the smallest amount of citric acid to drop the pH of anything I water to 5.8-6.0. Soil pH on average is now 6.8, which I’m much happier with. I like using pH measurement in my grow to give me info - many will say you don’t need to worry about pH with organics, this is true when things are going well, but it’s awfully handy to know what’s up when things aren’t.

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Nice. You get it.

PadawanWarrior said:

Nice. You get it.

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Haha thnx man, it’s been a road to get there

it’s frustrating I can’t dump the excess N…still getting (milder) N tox in veg this run. I’m going to plant some serious N hog veg after this run to pull out asmuch as I possibly can. I get a boner thinking about walking into my room and seeing an N def

lakesidegrower said:

My two cents… my well water is about 7.2 and 220ppm full of CaCO3 as well. I was having all kinds of def, lock out and pH issues showing up in my last run since using only well water. It got worse over time and it was only when I flushed, started using rain water and pHing my water to get things back on track. In fact, I think things are still balancing out. Running no-till, 3rd run. Picking up a Bluelabs pH soil pen was a huge help.

I think what was happening for me wastwo issues: too much N and an accumulation of CaCO3 over time in my pots, given there’s never any runoff.That was causing antagonism of Mg and K and I believe was also contributing to what I found to be an average soil pH of around 7.5 when I first checked. Have been using the smallest amount of citric acid to drop the pH of anything I water to 5.8-6.0. Soil pH on average is now 6.8, which I’m much happier with. I like using pH measurement in my grow to give me info - many will say you don’t need to worry about pH with organics, this is true when things are going well, but it’s awfully handy to know what’s up when things aren’t.

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Also, as I stated earlier, high ppm and high pH tap/well water tend to be high in bicarbonates. Calcium carbonate isn't a readily available source of calcium to begin with, and bicarbonates will make most calcium carbonate inaccessible to the plant. Calcium carbonate is best used as a soil amendment and let breakdown for awhile as it's the primary driver of soil chemistry and is responsible for oxygen levels in the soil. Calcium is also the main nutrient that 99% of soils don't have enough of(even in all the fancy amended soils people use). Oxygen happens to be the most important element in the soil--especially for the roots and the microbes. Readily available forms of calcium are gypsum, amino acid chelated calcium, and calcium carbonate (oyster shell, calcitic lime, bone meal) that has been "cooked" in ewc or compost. For the plant to integrate calcium into it's structure, there must be sufficient boron as well.

Edit- I agree that knowing the pH of your water/nutrient solutions is important in organics. It's also important to know the exact chemical composition of the soil via a soil analysis. However, both are useless if a person doesn't know what they mean.

I wouldn't use citric acid as a ph down, as it will kill your bacterial microbes. Stick with phosphoric acid.

Unsulfured Molases will bring the ph down and fast ... i think lol

PJ Diaz said:

I wouldn't use citric acid as a ph down, as it will kill your bacterial microbes. Stick with phosphoric acid.

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Tell me more about that / why would the citric kill the microbes and not the phosphoric acid? My understanding is that the citric acids function simply lies in the solution being at an extremely acidic pH which pests cannot tolerate. I can certainly see this affecting the microbes on the leaf tho.

My general foliar recipes that aren’t ipm contain LAB as well, so hopefully I’m restoring that micro biome on the leaf a bit. I tend to only do a citric if there’s a large outbreak of something, it can be pretty harsh on the older fans. I prefer insecticidal soaps, essential oils and neem for regular ipm.

swedsteven said:

Unsulfured Molases will bring the ph down and fast ... i think lol

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Yea I find that as well, I like citric because it won’t mess up my blumat lines - but I usually see molasses bringing the pH right in range when I use it in compost teas

Brawndo G said:

Also, as I stated earlier, high ppm and high pH tap/well water tend to be high in bicarbonates. Calcium carbonate isn't a readily available source of calcium to begin with, and bicarbonates will make most calcium carbonate inaccessible to the plant. Calcium carbonate is best used as a soil amendment and let breakdown for awhile as it's the primary driver of soil chemistry and is responsible for oxygen levels in the soil. Calcium is also the main nutrient that 99% of soils don't have enough of(even in all the fancy amended soils people use). Oxygen happens to be the most important element in the soil--especially for the roots and the microbes. Readily available forms of calcium are gypsum, amino acid chelated calcium, and calcium carbonate (oyster shell, calcitic lime, bone meal) that has been "cooked" in ewc or compost. For the plant to integrate calcium into it's structure, there must be sufficient boron as well.

Edit- I agree that knowing the pH of your water/nutrient solutions is important in organics. It's also important to know the exact chemical composition of the soil via a soil analysis. However, both are useless if a person doesn't know what they mean.

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I keep debating a soil test, but then I figure that I might just use another mix in the no till pots and start again - incorporate more of what I’ve learned over the past year into the mix and then go to testing.

but who can’t argue with testing - can’t beat it if you want to understand your soil, especially if you run no-till.

i don’t think you necessarily need it to solve an issue you are experiencing,for example. It will likely take longer, require more persistence and perhaps trial and error to arrive at a proper diagnosis and remedy, but the experience in getting there is invaluable. Albeit frustrating lol this is what makes the test so attractive.

also your description of Ca / CaCO3 is pretty much how I understand it as well. The extension of that which I find to be important is that a build up of excess CaCO3 is still a build up a Ca; whether it is in an available form to the plant or not, it will interact with surrounding minerals, and in excess proportions it will cause antagonism of micros and macros (namely K, Mg, and P) , and can also buffer the pH higher in your pots leading to issues with availability in that respect as well.

my take is that you need to account for Ca content in your water and then build your soil accordingly. But you have to account for all of the Ca that’s in there, including any that might be in rock dusts or other organic amendments

PJ Diaz said:

I wouldn't use citric acid as a ph down, as it will kill your bacterial microbes. Stick with phosphoric acid.

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Where'd you get that idea?

PadawanWarrior said:

Where'd you get that idea?

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From my hydroponics professor who has a master's degree in horticulture. Citric acid is bactericidal.

PJ Diaz said:

From my hydroponics professor who has a master's degree in horticulture. Citric acid is bactericidal.

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Hmmm. I need to do some research. I was under the impression it was fine as long as you don't use too much.

PadawanWarrior said:

Hmmm. I need to do some research. I was under the impression it was fine as long as you don't use too much.

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I was under the same impression, but I can see how it would impact microbes on a leaf surface. I imagine again, that it’s the extremely low pH that most microbes couldn’t tolerate. Who knows what the contact time is tho, that for me would be the important piece of info

lakesidegrower said:

I was under the same impression, but I can see how it would impact microbes on a leaf surface. I imagine again, that it’s the extremely low pH that most microbes couldn’t tolerate. Who knows what the contact time is tho, that for me would be the important piece of info

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I think we're correct and that it's fine as long as you don't use too much. Same with phosphoric acid. I'm pretty sure it's just the low pH that kills them.

PadawanWarrior said:

Hmmm. I need to do some research. I was under the impression it was fine as long as you don't use too much.

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PadawanWarrior said:

I think we're correct and that it's fine as long as you don't use too much. Same with phosphoric acid. I'm pretty sure it's just the low pH that kills them.

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I guess that begs the question, how much is too much? Since you need more citric acid than you do phosphoric acid to achieve the same amount of "ph down", then you are running a higher risk of killing microbes. Admittedly I was surprised when he told me that, but he's the chair of the horticulture department, and has a master's degree, so I have to assume that he knows what he's talking about.

PJ Diaz said:

I guess that begs the question, how much is too much? Since you need more citric acid than you do phosphoric acid to achieve the same amount of "ph down", then you are running a higher risk of killing microbes. Admittedly I was surprised when he told me that, but he's the chair of the horticulture department, and has a master's degree, so I have to assume that he knows what he's talking about.

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I wasn't under the impression that the guys at the hydro shop that have been growing for 20 years would know what they were talking about too. But I was way off, lol.

Chair of what horticulture department?

PadawanWarrior said:

I wasn't under the impression that the guys at the hydro shop that have been growing for 20 years would know what they were talking about too. But I was way off, lol.

Chair of what horticulture department?

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I'm not gonna name the school, but the guy does also grow hemp in one of the College greenhouses. They guys at the hydro shop haven't gone to school for several years to study horticulture in all likeliness, or they would be working somewhere else.

swedsteven said:

Unsulfured Molases will bring the ph down and fast ... i think lol

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With my mollases ph went up like crazy.maybe it wasnt unsulfured

Giving my plants citric acid water with yucca tonight. 1/16 tsp per gal. I could double it though no problem.

PadawanWarrior said:

Giving my plants citric acid water with yucca tonight. 1/16 tsp per gal. I could double it though no problem.

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Citric acid won't hurt your bacteria. I've heard that before, but it's just because it's used as a preservative in canning, but it's not the citric acid itself, just the very low PH that you end up with. I used to can tomatoes and I think I used something like 1/2 teaspoon per jar, which makes it extremely acidic. With my water, with Jack's added, I use about 1/2 teaspoon citric acid per 4 gallons to bring ph down to 6. It's much better for a living medium than phosphoric acid just because high levels of phosphorus suppress the microbiome.

PadawanWarrior said:

Giving my plants citric acid water with yucca tonight. 1/16 tsp per gal. I could double it though no problem.

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Rurumo said:

Citric acid won't hurt your bacteria. I've heard that before, but it's just because it's used as a preservative in canning, but it's not the citric acid itself, just the very low PH that you end up with. I used to can tomatoes and I think I used something like 1/2 teaspoon per jar, which makes it extremely acidic. With my water, with Jack's added, I use about 1/2 teaspoon citric acid per 4 gallons to bring ph down to 6. It's much better for a living medium than phosphoric acid just because high levels of phosphorus suppress the microbiome.

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