Raising pH safely?

Offmymeds

Offmymeds

Well-Known Member
I've got an autoflower in a fresh mix of 50/50 peat moss & vermiculite. I also added dolimitic lime & gypsum to the mix in the amounts recommended by the famous Dr. Bugbee. I never tested the pH originally. The plant is only 3 weeks old & just got a 4th set of leaves so it's still small. It's in a 5 gallon pot in the pic below. There's a little odd curling in 2 leaves but otherwise looks good.

My nutes went in this AM at pH of 6.3 & the runoff tested at 4.0 with the ppm in & out about the same.

I'm kinda shocked how low the pH was & obviously need to adjust but how?

I read that lime might actually take months to fully adjust. Do I spread the surface with lime? Do I flush? Do I raise the nutes pH & how much?

IMG_20210125_114751920_HDR.jpg
 
Renfro

Renfro

Well-Known Member

Medium pH Correction (Soil and Coco)

Checking and adjusting the pH of your root zone in soil or coco is a very important part of growing healthy plants. Often you will notice nutrient deficiencies despite the fact you know you have provided an ample feed at an appropriate pH level. When this happens it’s generally either...
www.rollitup.org
 
Offmymeds

Offmymeds

Well-Known Member
Renfro said:

Medium pH Correction (Soil and Coco)

Checking and adjusting the pH of your root zone in soil or coco is a very important part of growing healthy plants. Often you will notice nutrient deficiencies despite the fact you know you have provided an ample feed at an appropriate pH level. When this happens it’s generally either...
www.rollitup.org
Click to expand...
I have the GH Up but I'm a little weary of adding nutes at a pH of 9 to go from 4.0 to 6.5.
 
getogrow

getogrow

Well-Known Member
Offmymeds said:
I have the GH Up but I'm a little weary of adding nutes at a pH of 9 to go from 4.0 to 6.5.
Click to expand...
First off, look at the plant. she is going slow but looking great. Ph is not hindering you right now. i dont need a meter to see that.
Run off is not really much to go on. 90% of the time , you disregard run off. 10% of the time you may get some useful info from it.

It can take awhile for the lime to start working but she is still little in a giant pot.....give it time. This is one of the many reasons i dont start with bigger pots but that dont mean its not possible. Thats just me.
How much lime did you add to the 5 gallons ?
Your ph of your medium is NOT 4.0.
 
Offmymeds

Offmymeds

Well-Known Member
Thank you. I don't panic like I used to. I killed a bunch of plants with a bad pH meter once.

I used 40 grams/cubic ft so 26.8 grams.

I am considering getting a soil pH meter.
 
Renfro

Renfro

Well-Known Member
Offmymeds said:
I am considering getting a soil pH meter.
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Just make sure to avoid the cheap analog ones with the long thin metal probe/s, they arent accurate at all, I have seen them read the opposite of whats really going on lol. A bad meter can do more harm than no meter at all. Make sure you can trust your measurements before trying to make corrections.

Right now those are just starting to get old enough that they will exist on food intake, prior they were on seed reserves. So you will know soon how they like the root zone / uptake.
 
DoubleAtotheRON

DoubleAtotheRON

Well-Known Member
True!, I have done hard corrections with a 10.5-11 mix to fix a 5.5 soil. It sounds crazy, but they take it well. I only had to do it once, and made sure I got plenty of runoff. After that, maybe one more at 8ph , then it will level off in the mid 6’s, and I can feed in at 7- 7.3 after that. They were pretty sick tho, and the hard correction worked, I’ve done it on a couple hundred plants, but I have a very good ph meter.
 
SnoopyDoo

SnoopyDoo

Well-Known Member
Do you have beneficials in the soil? I've had to use Renfro's method for correcting PH and it is a good one. If this product is available in your area, about 1-2 tablespoons of Espoma Lime top dressed and mixed into the peat will (probably) correct your PH issue. I had a hydro system that kept dropping to 4.0 and the lime fixed it. I didn't like PH'ing a 100 gal reservoir to 8.0 every other day, so I'm a fan of the Espoma Garden Lime - it's fast acting compared to dolomite lime.

As getogrow said, the PH of your soil isn't 4.0 or that little plant would be hurting if not dead. Is it possible there is something in the runoff saucer that is throwing off your PH measurement? I've been burned by faulty PH pens, so I use the drops (aka cabbage juice).

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Offmymeds

Offmymeds

Well-Known Member
SnoopyDoo said:
Do you have beneficials in the soil? I've had to use Renfro's method for correcting PH and it is a good one. If this product is available in your area, about 1-2 tablespoons of Espoma Lime top dressed and mixed into the peat will (probably) correct your PH issue. I had a hydro system that kept dropping to 4.0 and the lime fixed it. I didn't like PH'ing a 100 gal reservoir to 8.0 every other day, so I'm a fan of the Espoma Garden Lime - it's fast acting compared to dolomite lime.

As getogrow said, the PH of your soil isn't 4.0 or that little plant would be hurting if not dead. Is it possible there is something in the runoff saucer that is throwing off your PH measurement? I've been burned by faulty PH pens, so I use the drops (aka cabbage juice).

pH Test Indicator Drops for Growing Microgreens - Measure pH of Water | True Leaf Market Seed Company

Free Shipping. Measure the pH of your water for microgreens. Includes instructions on the label for measuring and comparing to the pH scale. Microgreen...
www.trueleafmarket.com www.trueleafmarket.com

Click to expand...
getogrow said:
Espoma Garden Lime
I can also say that this breaks down fairly quick....its water soluble and works great.
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I just grabbed my drain pan that had been sitting there for a few weeks so that is a good possibility. Normally I rinse everything before storing but the space hasn't been organized so I may have overlooked rinsing it.

My local Lowes has the lime & it's cheap. Thank you.

I put bennies in the nutes.
 
pulpoinspace

pulpoinspace

Well-Known Member
your plant looks good i'd think twice before doing anything.

why are you measuring the pH of your runoff and what are you measuring it with? What was the EC of the solution when it went in and what was the EC of the runoff?
 
Offmymeds

Offmymeds

Well-Known Member
pulpoinspace said:
your plant looks good i'd think twice before doing anything.

why are you measuring the pH of your runoff and what are you measuring it with? What was the EC of the solution when it went in and what was the EC of the runoff?
Click to expand...
I thought the runoff is an indicator of the soil condition. I use a good liquid pH meter. Apera PH-60. ppm in was 848 & out at 822. I have the cheap ppm meter with no EC reading.
 
pulpoinspace

pulpoinspace

Well-Known Member
Offmymeds said:
I thought the runoff is an indicator of the soil condition. I use a good liquid pH meter. Apera PH-60. ppm in was 848 & out at 822. I have the cheap ppm meter with no EC reading.
Click to expand...
hmmm thats interesting. maybe its the peat moss is a little acidic or not enough lime? Either way the plant looks good so far. id follow the advice in post #2 but air on the side of caution, i'd probably feed ~7 ph next time.
 
Offmymeds

Offmymeds

Well-Known Member
It's starting to curl a little more but still looks healthy otherwise. I ran my runoff through 1 gallon of the peat/vermiculite mix and the pH of that runoff dropped 1.5. I then ran RO pH 7 through it & it came up a half notch. The mix is porous enough to water every day. I hope 2 straightt days of 7.0 nutes with good runoff should be enough.

That's the plan anyway.
 
DougsNugggs

DougsNugggs

Member
Offmymeds said:
I've got an autoflower in a fresh mix of 50/50 peat moss & vermiculite. I also added dolimitic lime & gypsum to the mix in the amounts recommended by the famous Dr. Bugbee. I never tested the pH originally. The plant is only 3 weeks old & just got a 4th set of leaves so it's still small. It's in a 5 gallon pot in the pic below. There's a little odd curling in 2 leaves but otherwise looks good.

My nutes went in this AM at pH of 6.3 & the runoff tested at 4.0 with the ppm in & out about the same.

I'm kinda shocked how low the pH was & obviously need to adjust but how?

I read that lime might actually take months to fully adjust. Do I spread the surface with lime? Do I flush? Do I raise the nutes pH & how much?

View attachment 4806772
Click to expand...
Amend and continue normal feeding and PH

check run off after 5 days.

continue to amend if needed.

Less is more
 
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