Fastest way to acidify?

epenna · June 5, 2018

I am growing in 15 gallon containers.

The tomato plants are getting enough water and fertilizer, but the PH test comes out neutral, a 7, and the plants are not doing as well as I would wish.

I've read that any attempt to bring down the ph by .5 or so will take months.

Is this correct? Or does anyone have a better idea?

Thanks,

E

zipcode · June 6, 2018

7 is certainly not bad. Are you measuring the runoff or where? Try the runoff, if it's not doing well I'm guessing it's more around 8+. How well do you wish them to be exactly?
First, change the fertilizer. Second, use sulfuric acid ideally (if not, powder citric) to adjust water at each watering. What's your water source? Watering every time with proper pH water should keep the plants in ok state even if the longterm pH is much higher, the temporary lower pH will be enough to absorb those microelements.

Worth1 · June 6, 2018

5% acidity vinegar 4 to 6 tablespoons per gallon of water will make them jump out of their containers with growth if all else is correct.
This should happen in about a day or two maybe three to show results not months.
I personally dont think 7 is anywhere close to the right PH for tomatoes.
It is on the upper limit of where it should be around 6 which is 10 times more acidic than 7.
What you might have to worry about is too many locked up nutrients being released all of a sudden.

AKmark · June 6, 2018

Phosphoric acid.

Worth1 · June 6, 2018

Quote:

Originally Posted by AKmark

Phosphoric acid.

How much ospho per gallon of water.

AKmark · June 6, 2018

Quote:

Originally Posted by Worth1

How much ospho per gallon of water.

Just a couple of drops. It is not linear, so you really have to be careful. Let's say I use an ounce per 100 gallons and my pH moves from a 7 to 6.5, a few more drops may take it down to a 6. You can find it in most hydro stores labeled pH down, it is the orange Jim Jones koolaid looking stuff.

**Lee** · June 6, 2018

So does that mean I should feed my plants a Coke if I want the pH to lower?

4th ingredient is Phosphoric acid....

AKmark · June 6, 2018

Quote:

Originally Posted by Lee

So does that mean I should feed my plants a Coke if I want the pH to lower?

4th ingredient is Phosphoric acid....

You should try it and let us know how it works out? LOL

epenna · June 6, 2018

You guys are great!

Thanks for the info!

E

zipcode · June 7, 2018

Phosphoric acid is risky. I used it and prefer citric (I would use sulfuric but don't have any). The problem is if you have high alkalinity water (tap water usually) and use phosphoric, the amount of phosphorous you add is significant and you get worse nutrient lock than due to the high pH. It has happened to me last year.
Probably the best long term solution would be humic/fulvic, since they are stable in soils, if you find any reasonably priced source (somewhat unlikely, at least currently).

Edit: in case the 'change the fertilizer' was not quite clear, there are fertilizers with overall acidifying effect or the opposite (talking about the chemical ones), you should look at the exact composition. Not sure about the organic fertilizers, there is conflicting information about this out there, but in my experience they're mostly neutral in the long term.

Worth1 · June 7, 2018

I read on a pot growing site that sulfuric was more stable.
I think my containers are starting to get on the alkali side from the city water.
Not for sure just a wild guess.
Maybe it is just this horrible heat.
One thing is for sure I dont have any sign of BER what so ever and this was a concern.

TexasTomat0 · June 7, 2018

I use sulfuric acid to help acidity my soil for blueberry plants that I have growing in pots. It just takes a few drops per gallon. I measure with a ph meter. I lower the ph until I get about to a ph of 5 then I water.

I've read that the sulfuric acid reacts with calcium to create gypsum. Blueberries hate calcium so this is beneficial for them. I do not know if it would be a negative for tomatoes. I do know this will definitely acidity your soil.

You could also try fertilizing with ammonium sulfate.

epenna · June 7, 2018

Hey Worth1,

I took your advice and watered with vinegar water yesterday...

How often should I repeat this? Every time I water until the Ph tests come back near 6? Before the first watering, the Ph was 7-7.5.

Thanks!

E

AKmark · June 7, 2018

Quote:

Originally Posted by TexasTomat0

I use sulfuric acid to help acidity my soil for blueberry plants that I have growing in pots. It just takes a few drops per gallon. I measure with a ph meter. I lower the ph until I get about to a ph of 5 then I water.

I've read that the sulfuric acid reacts with calcium to create gypsum. Blueberries hate calcium so this is beneficial for them. I do not know if it would be a negative for tomatoes. I do know this will definitely acidity your soil.

You could also try fertilizing with ammonium sulfate.

I think that would only be in concentrates, you should not get a reaction otherwise. There is another commercial grower right up the road from me, we both use the exact same fertilizers, and methods, but he uses Sulfuric acid, I use Phosphoric acid, both of us produce a lot of tomatoes.

Worth1 · June 7, 2018

Quote:

Originally Posted by epenna

Hey Worth1,

I took your advice and watered with vinegar water yesterday...

How often should I repeat this? Every time I water until the Ph tests come back near 6? Before the first watering, the Ph was 7-7.5.

Thanks!

E

I only did it about every two weeks with raised beds.
Real depends on the water flushing the vinegar out.

More tonight when I get home.
Worth

June 5, 2018	#1
epenna Tomatovillian™ Join Date: Apr 2017 Location: Glendale, CA Posts: 17	Fastest way to acidify? I am growing in 15 gallon containers. The tomato plants are getting enough water and fertilizer, but the PH test comes out neutral, a 7, and the plants are not doing as well as I would wish. I've read that any attempt to bring down the ph by .5 or so will take months. Is this correct? Or does anyone have a better idea? Thanks, E

June 6, 2018	#7
Lee Tomatopalooza™ Moderator Join Date: Jan 2006 Location: NC-Zone 7 Posts: 2,188	So does that mean I should feed my plants a Coke if I want the pH to lower? 4th ingredient is Phosphoric acid.... __________________ Intelligence is knowing a tomato is a fruit. Wisdom is knowing not to put one in a fruit salad. Cuostralee - The best thing on sliced bread.

June 7, 2018	#10
zipcode Tomatovillian™ Join Date: Jun 2010 Location: Romania/Germany , z 4-6 Posts: 1,582	Phosphoric acid is risky. I used it and prefer citric (I would use sulfuric but don't have any). The problem is if you have high alkalinity water (tap water usually) and use phosphoric, the amount of phosphorous you add is significant and you get worse nutrient lock than due to the high pH. It has happened to me last year. Probably the best long term solution would be humic/fulvic, since they are stable in soils, if you find any reasonably priced source (somewhat unlikely, at least currently). Edit: in case the 'change the fertilizer' was not quite clear, there are fertilizers with overall acidifying effect or the opposite (talking about the chemical ones), you should look at the exact composition. Not sure about the organic fertilizers, there is conflicting information about this out there, but in my experience they're mostly neutral in the long term. Last edited by zipcode; June 7, 2018 at 08:33 AM.

June 6, 2018	#3
Worth1 Tomatovillian™ Join Date: Feb 2006 Location: Den of Drunken Fools Posts: 38,539	5% acidity vinegar 4 to 6 tablespoons per gallon of water will make them jump out of their containers with growth if all else is correct. This should happen in about a day or two maybe three to show results not months. I personally dont think 7 is anywhere close to the right PH for tomatoes. It is on the upper limit of where it should be around 6 which is 10 times more acidic than 7. What you might have to worry about is too many locked up nutrients being released all of a sudden.

June 6, 2018	#4
AKmark Tomatovillian™ Join Date: Jun 2013 Location: Wasilla Alaska Posts: 2,010	Phosphoric acid.

June 7, 2018	#12
TexasTomat0 Tomatovillian™ Join Date: Mar 2017 Location: Central Texas - Zone 8A Posts: 196	I use sulfuric acid to help acidity my soil for blueberry plants that I have growing in pots. It just takes a few drops per gallon. I measure with a ph meter. I lower the ph until I get about to a ph of 5 then I water. I've read that the sulfuric acid reacts with calcium to create gypsum. Blueberries hate calcium so this is beneficial for them. I do not know if it would be a negative for tomatoes. I do know this will definitely acidity your soil. You could also try fertilizing with ammonium sulfate.