Author Topic: Adjusting container/potting mix ph?  (Read 886 times)

dross99_si

  • Member
  • ***
  • Posts: 155
    • SE Florida zone 10a
    • View Profile
Adjusting container/potting mix ph?
« on: March 13, 2020, 02:27:45 PM »
We’ve been using Espoma soil acidifier every 2 months as the label instructs on our potted mango trees. Anybody have a better or more efficient way of keeping container soil acidic? We’re forced to hand water with the hose during dry periods as we live in HOA and use a Boogie Blue Plus filter to help with chlorine & chloramines but we all know city water ph is alkaline.

I know people suggest adding peat or pine needles or using acid fertilizer like holly tone or down to earth acid lover fertilizer but it seems no matter what we add to the potting mix, if we continue to use alkaline water to irrigate I don’t think the ph will ever reach optimal range in our containers.
Therefore I am thinking we need to focus on adjusting the water ph.
Some of you mentioned using rain water exclusively which is a great idea, but we have no way to collect and store that much rain water.
I have now begun to investigate reverse osmosis systems. The other option is possibly adding some (soil biology -safe) acid to the hose water either through injection or mixing in a large vessel and water the plants that way.

My first thought was citric acid like lemon juice, but some articles state citric acid will kill soil microbes. No good.

Even then, adding acid to the hose water may fix ph but we still have the ppm or tds factor..

On another note, we have calibration solutions being delivered tomorrow to check the accuracy of our ph meter.

Any insight or suggestions? Squam, Guanabanas, Cookie?
« Last Edit: March 13, 2020, 02:45:36 PM by dross99_si »

Daintree

  • Hero Member
  • *****
  • Posts: 941
    • Boise, Idaho - zone 6, with a zone 12 greenhouse...
    • View Profile
Re: Adjusting container/potting mix ph?
« Reply #1 on: March 13, 2020, 05:42:16 PM »
That seems like a lot of sulfur you are adding.  What is the pH of the mix you are using? Mine is around 6 to 6.5 to begin with. I add pH Down to the water to drop it to around 5.8 or so, which is the approximate pH of rainwater. I only add the Espoma sulphur about once a year.  Our water comes out of the hose at about 7.8 - 8.6.

Oolie

  • Hero Member
  • *****
  • Posts: 987
    • San Diego
    • View Profile
Re: Adjusting container/potting mix ph?
« Reply #2 on: March 13, 2020, 06:12:14 PM »
Like CM stated in your previous thread on the subject, Mango will handle the high pH just fine.

I wouldn't worry so much about the alkalinity of the tap water, as the room in the pot for roots.

SeaWalnut

  • Hero Member
  • *****
  • Posts: 1397
    • Romania zone 6
    • View Profile
Re: Adjusting container/potting mix ph?
« Reply #3 on: March 13, 2020, 07:01:18 PM »
That seems like a lot of sulfur you are adding.  What is the pH of the mix you are using? Mine is around 6 to 6.5 to begin with. I add pH Down to the water to drop it to around 5.8 or so, which is the approximate pH of rainwater. I only add the Espoma sulphur about once a year.  Our water comes out of the hose at about 7.8 - 8.6.
Ph doesnt matter if its big.Important is how much buffer it has in it.
I can show you rain water with 8 ph that becomes 6 after you add just a drop of acid  and tap water with 7,5 ph that you add 100 drops of acid to make it 6.

SeaWalnut

  • Hero Member
  • *****
  • Posts: 1397
    • Romania zone 6
    • View Profile
Re: Adjusting container/potting mix ph?
« Reply #4 on: March 13, 2020, 07:07:59 PM »
First of all what is your ph?
If you have a ph more than 8,5 then you have sodic soil( alkaline soil) and you can lower it easily by using gypsum.
The gypsum you can buy it at constructions depot for cheap in the form of powder bags or even plaster boards if you need more ( damaged plaster walls/ drywall from demolition).
Using an acid is also a good idea and for that i use pyroligneous acid wich its liquid smoke and its made of humic and fulvic acids.
I add it to the water and measure the ph until the water becomes 4,5-5 ph.
The more buffer the water has,the more acid you use and you need a measuring tool for ph.

dross99_si

  • Member
  • ***
  • Posts: 155
    • SE Florida zone 10a
    • View Profile
Re: Adjusting container/potting mix ph?
« Reply #5 on: March 13, 2020, 10:40:06 PM »
To be clear we are talking about mango trees and other tropicals in pots.
I add the Espoma soil acidifier as directed, but it doesn’t seem to do much. I am starting to think that applying city water with ph right around 8 keeps our potting mix alkaline no matter what amendments I add. This is why I am now looking to make adjustments to the water. Either adding some form of acid or investing in a reverse osmosis system. I need to get a tds/ppm meter as well.

Oolie

  • Hero Member
  • *****
  • Posts: 987
    • San Diego
    • View Profile
Re: Adjusting container/potting mix ph?
« Reply #6 on: March 13, 2020, 11:10:38 PM »
Reverse Osmosis, or RO is good for removing Dissolved Solids, or TDS, which softens the water, but is not really going to do much for the soil pH as neutral water doesn't affect the overall pH, especially in a buffered soil condition.

These factors are more critical in arid climates where the soil media will be drier more often.

I wouldn't worry about it, it's not like Southern California with water coming from the Colorado river that is already very hard, and the climate is especially arid.

Are the plants you are growing Acid lovers? Hydrangea? Blueberry?

Many I have spoken with say that adding soil sulfur on the top of the container media is enough to keep the pH down for these types of plants. Since your climate is not all that arid, it should work well enough.

S + H2O => HSO4 + H

The hydrogen ions produced will keep the pH down.

SeaWalnut

  • Hero Member
  • *****
  • Posts: 1397
    • Romania zone 6
    • View Profile
Re: Adjusting container/potting mix ph?
« Reply #7 on: March 13, 2020, 11:11:15 PM »
You dont need TDS meter except the case you get a reverse osmosis filter.The ph meter its more important.
Also i reccomend the ebay TDS meter ( hand held) made in China.
Costs @ 5 -10 dollars and its verry accurate .
Beware that somme scammers rebrand them and sell them for like 100dollars.


Also ,as an acid you can use vinegar.Diluted vinegar will also increase the microbial activity by a lot becase its a carbon source.
Basically the vinnegar grades ,5-10 tells you how much carbon you add and its like adding a little sugar in the water wich has 100 grades.
Vinegar its good but i prefer pyroligneous / humic acid wich ,btw,its also called wood vinegar.
« Last Edit: March 13, 2020, 11:16:32 PM by SeaWalnut »

dross99_si

  • Member
  • ***
  • Posts: 155
    • SE Florida zone 10a
    • View Profile
Re: Adjusting container/potting mix ph?
« Reply #8 on: March 14, 2020, 07:19:11 AM »
Thanks guys. We have so many things in pots including mango, avocado, peach, several different annona, blueberry, jaboticaba, hydrangea, abiu, ice cream bean, tamarind, on and on. Just trying to make container environment as hospitable as possible.

As far as the TDS I am just curious to see how much is in our hose water. I got one on Amazon for $13. It had tons of good reviews.
Also picked up a new ph meter.

When topdressing with sulfur, the Espoma and Jobes brands are 30% S + gypsum which is what we've been using. I also see Southern Ag and others make 90% sulfur soil acidifying prills. Would those be too strong or overkill? They don't list container growing application rates on the label.

I will do research on adding pyroligneous / humic acid to the irrigation water as well. Thanks for that recommendation.

As soon as the new meters arrive in the mail I will update with the ph & TDS of the water that comes out of our hose.

 

SMF spam blocked by CleanTalk