Adjusting PH in soil

[Pouatchee]

Hi fellow growers,

I am wondering how you guys lower the PH in your soil. Lowering PH in water is easy enough but soil... that is a whole different ball game. Yesterday I asked my better half to order sulphur as it seems to do the job according to my queries on the internet. I keep reading about 'elemental sulphur' but is is impossible to find here so I will try sulphur straight up.

 

A solution I tried was to make my water for watering the plants at a PH of 6.0 but the PH of my dirt is stuck at 7.0 to 6.8. I want to get it down around 6.2-6.4 which is, so far, near impossible to do. Raising the PH is a cinch, just add baking soda. If anyone out there has a solution to solve this problem I am sure it will help quite a few people here. 

 

 

 

[papa al]

Elemental sulfur is sulphur straight up.

The yellow stuff.

//////

Could take quite bit of product

and considerable time thru bacterial action

to change pH

depending on your soil type.

A soil sample to a chemist/agronamist.

would be most definitive.

[Pouatchee]

16 minutes ago, papa al said:

A soil sample to a chemist/agronamist.

would be most definitive.

The soil comes from Megahome. Question is... what do people use to lower the PH?

I read that acid can be used. Just hoping for a simple solution to a seemingly difficult problem  ; (

[papa al]

Well...

If there was a  simple solution

the problem would not be difficult.

Would it now...?

Muriatic acid would lower the pH for sure.

 

[zyphodb]

Adding vinegar (acetic acid) should do it...

 

[indyo]

what kind of medium?, if you are in coco you can watering at 5,5 but before flush the roots and then check again the dirty, try to have at least 10% dirty when watering, so salts don't build up in your medium.

[Pouatchee]

2 hours ago, indyo said:

what kind of medium?

 I am in soil. Dirt purchased at Megahome Hardware store and 20% my household compost. 

 

2 hours ago, zyphodb said:

Adding vinegar (acetic acid) should do it..

Hmmm everything I read about vinegar suggests otherwise

 

3 hours ago, papa al said:

Well...

If there was a  simple solution

the problem would not be difficult.

Would it now...?

Muriatic acid would lower the pH for sure.

Hmmm...

--> Muriatic Acid and Soil

Like any acidic substance, muriatic acid can technically be used to neutralize soil, if you use enough of it. However, it is not generally a good option because of how caustic it is. When put into the soil, muriatic acid does not necessarily degrade very much.

https://homeguides.sfgate.com/muriatic-acid-safe-acidify-soil-gardens-80524.html

 

No simple solution for sure. I just can't believe that there are so few answers and solutions out there. Darn, am I one of the few who has encountered this problem? Seems doubtful.????

[Mr Meeseeks]

For living soil water at 6.5 to 7.0 pH. 

 

For coco, peat moss and other inert mediums fertigate at 5.8 to 6.2 pH.

 

For deep water culture systems a pH of 5.5 is required.

 

That's it. 

[Pouatchee]

5 minutes ago, Mr Meeseeks said:

For living soil water at 6.5 to 7.0 pH. 

 

For coco, peat moss and other inert mediums fertigate at 5.8 to 6.2 pH.

 

For deep water culture systems a pH of 5.5 is required.

 

That's it. 

And will that lower the PH of the soil? If so, does it take many waterings before reaching desired PH?

[Pouatchee]

After some research I have found that wood vinegar has a ph of 2.5-3.0 and can be diluted and used top water plants once a month. This might help reduce the ph. It is also, apparently, good to treat soil and compost prior to planting plants. Maybe this will work. 

 

Feedback and first hand experience are more than welcome.

[rice555]

1 hour ago, Pouatchee said:

After some research I have found that wood vinegar has a ph of 2.5-3.0 and can be diluted and used top water plants once a month. This might help reduce the ph. It is also, apparently, good to treat soil and compost prior to planting plants. Maybe this will work. 

 

Feedback and first hand experience are more than welcome.

I use WV for a bug spray, but, keep strong sublation off the plant.

I bought sulphur at a chem supply downtown. There's pic of a box of cali from

the Co. in BKK that sales all sorts of chem's on a Masa thread on the food Forum with the P/N. They will EMS their products.

rice555 

[wombat]

I'm curious why you want to lower the Ph if you're growing weed?

[Mr Meeseeks]

Baking soda also helps to raise the pH in soil. I experienced low pH in soil that I bought from a market here when I started growing and it locked out my plants and they grew stunted. Lesson learned. 

 

I would just keep watering at between 6.5 to 7.0 pH and it should be fine. for soil that's where you want to be.

[Pouatchee]

8 hours ago, wombat said:

I'm curious why you want to lower the Ph if you're growing weed?

5.8 – 6.2

 

Cannabis, like many plants, prefers slightly acidic soil conditions. It tolerates a wide pH range (5.0-7.0) without symptoms of bronzing or interveinal chlorosis (yellowing of top leaves), but pH levels outside of the optimal range of 5.8 – 6.2 will limit growth.Mar 5, 2020

 

Maybe this answers your question? I grew some feminized auto-flower last time and they came out <deleted>. I am narrowing down all the causes. PH was a big factor. Of course nutrients and watering are too... so are many others. But turns out plants like pot absorb nutrients best at a lower ph.

 

[Trippy]

Maybe for your next grow use a peat moss mix, instead of soil. 

I make my own using the peat, perlite, rice husk and a little coco husk. . All very cheap and ph neutral. 

[Pouatchee]

9 hours ago, Trippy said:

Maybe for your next grow use a peat moss mix, instead of soil. 

I make my own using the peat, perlite, rice husk and a little coco husk. . All very cheap and ph neutral. 

Hey Trippy,

PH neutral is not ideal for weed. Read my post just prior to yours. It tells which PH weed likes best. The best solution I found so far is to water with wood vinegar (which has a ph of 2.5-3.0) once or twice a month and dilute and adjust the ph with water to around 6.0-6.2.  as @Mr Meeseeks  recommends water at desired ph after that. I also always adjust my ph in the water using fish pond water ph reducer to get the ph I want. I will use sulphur and wood vinegar in my compost and soil to reduce the ph to around 6.2.

 

I used to do hydro with a ph of around 7 and the results were okish. I already see significant improvements in the color and grow rate even after a couple of days. If you are happy with a ph of 7.0 @Trippy then you will be a lot happier if you adjust your ph.

     

[Trippy]

1 hour ago, Pouatchee said:

Hey Trippy,

PH neutral is not ideal for weed. Read my post just prior to yours. It tells which PH weed likes best. The best solution I found so far is to water with wood vinegar (which has a ph of 2.5-3.0) once or twice a month and dilute and adjust the ph with water to around 6.0-6.2.  as @Mr Meeseeks  recommends water at desired ph after that. I also always adjust my ph in the water using fish pond water ph reducer to get the ph I want. I will use sulphur and wood vinegar in my compost and soil to reduce the ph to around 6.2.

 

I used to do hydro with a ph of around 7 and the results were okish. I already see significant improvements in the color and grow rate even after a couple of days. If you are happy with a ph of 7.0 @Trippy then you will be a lot happier if you adjust your ph.

     

I've been using soil-less mixes for many years with great results. I've never even heard of experienced growers using real soil in pots. But up to you, i was just trying to help.

[jaideedave]

On 2/3/2023 at 3:26 PM, Pouatchee said:

And will that lower the PH of the soil? If so, does it take many waterings before reaching desired PH?

I'm no expert but I think he needs to flush the whole thing because salts have built up and are probably in the root zone causing "nutrient lock".Flush with plain water 1st then with proper PH hen start feeding again. 

[Pouatchee]

19 minutes ago, Trippy said:

I've been using soil-less mixes for many years with great results. I've never even heard of experienced growers using real soil in pots. But up to you, i was just trying to help.

Seen some of that at Mega Home. I grew 20 years ago and have just come back into the game. I kinda am old school. Now they have feminized... photoperiod... auto-flower... It is taking some time to catch up.

 

What is the ph of soil-less medium? and how do you go about fertilizing? I will give it a try but if you have any inside info I am here to listen and learn. 

 

My main interest still remains the ph... as that is one of the corner stones to great weed, IMHO.

[Pouatchee]

22 minutes ago, jaideedave said:

I'm no expert but I think he needs to flush the whole thing because salts have built up and are probably in the root zone causing "nutrient lock".Flush with plain water 1st then with proper PH hen start feeding again. 

That is not the issue at this point. The soil is brand new and has never been used before. I have 6 inch plants and seedling just starting up I also used the soil for cucumbers and since lowering the ph I am seeing great results. The PH is something overlooked by most soil medium growers. Hydroponic growers are more into this usually in my experience from when I did hydro.

 

Right now I just want to set myself up with strong mother plants from different strains then I might start cloning them and go back to hydro. I was out of the game for over 20 years but seeing how the regulations have changed my interest has spiked again.

[Trippy]

22 hours ago, Pouatchee said:

Seen some of that at Mega Home. I grew 20 years ago and have just come back into the game. I kinda am old school. Now they have feminized... photoperiod... auto-flower... It is taking some time to catch up.

 

What is the ph of soil-less medium? and how do you go about fertilizing? I will give it a try but if you have any inside info I am here to listen and learn. 

 

My main interest still remains the ph... as that is one of the corner stones to great weed, IMHO.

I'm no scientist, but I don't believe a soil-less medium changes the PH of the water you add to it. When I first started I would check the run-off from the pot and it was always very close to the PH of the water I added, so never checked again. If I even suspect a nutrient lock, I just give it plain PH adjusted filtered water, and it clears it up right away. Even in flowering I never give the plant more than 2 nutrient feedings in a row, so I never have the salts build up.

Bottom line, I never worry about my medium after the pots are filled. And I used to grow 100 plants at a time in California.

[Pouatchee]

14 minutes ago, Trippy said:

I'm no scientist, but I don't believe a soil-less medium changes the PH of the water you add to it.

Question is, what is the PH of soilles medium? Can't find a clear answer on Google, also, if I water with a lower PH water will that reduce the PH of the medium?

 

If yes, how long before it does?

 

[Trippy]

13 minutes ago, Pouatchee said:

Question is, what is the PH of soilles medium? Can't find a clear answer on Google, also, if I water with a lower PH water will that reduce the PH of the medium?

 

If yes, how long before it does?

 

Unlike soil, the soil-less doesn't retain the nutrients and remains neutral. So the PH of the medium is really a moot point. I also throw away the medium in between grows and start with fresh everytime. It's full of roots anyways and unusable.

Like I said, I'm no scientist, I'm only telling you what works for me.

[seajae]

well decomposed compost is probably the best natural way, sulphur is the other, these are probably the most used methods to do so, personally I use compost but only around each of my trees. Really depends on what you intend to  do, if it just a garden bed its easy but over a big area it does become difficult, I have around 1000 trees(plumeria/frangipani), each has a hole dug for it, filled with coir chip then some sand and compost added and mixed in, I also add a small amount of fine rock phosphate dust(great for roots) at the same time.  Every year I then add a slow release fertilizer & a good animal compost and turn it in, this keeps my PH around 6/6.5, I also add more coir chips as required. 

[Mr Meeseeks]

On 2/6/2023 at 9:43 AM, Trippy said:

Unlike soil, the soil-less doesn't retain the nutrients and remains neutral. So the PH of the medium is really a moot point. I also throw away the medium in between grows and start with fresh everytime. It's full of roots anyways and unusable.

Like I said, I'm no scientist, I'm only telling you what works for me.

I reuse my coco coir and perlite. On my third run now with the same medium and it is doing great! 

[Trippy]

On 2/12/2023 at 5:19 PM, Mr Meeseeks said:

I reuse my coco coir and perlite. On my third run now with the same medium and it is doing great! 

Isn't it full of roots?

[Pouatchee]

6 minutes ago, Trippy said:

Isn't it full of roots?

When  I am done with my soil I am planning on shredding the roots and keeping them as mulch in the soil. As far as I am concerned it probably is good for soil drainage. But good point. If anyone has opinions to the contrary please do share.

[Mr Meeseeks]

2 hours ago, Trippy said:

Isn't it full of roots?

I let it dry our thoroughly and break it down to take most of the root material out before reuse. 

 

I think about three runs is the max I'll get out of it but the plants are thriving on this third run so never know.

 

Remember that coco coir is inert so it really is just filler material in a hydroponic setup to absorb and hold the nutrients until the plants feed.

[SamuiGrower]

Lots of misinformation here on the subject. 
Do not use vinegar for pH down and do not use baking soda for pH up. Acetic acid has very weak bonds and its effects are extremely temporary. Baking soda, while raising pH through bicarbonate anions (HCO3), will add excessive sodium (Na) to the amount of about 43% by weight. Sodium should be avoided when growing cannabis. Use citric acid and potassium hydroxide. Both are readily available.

 

The stated pH of 5.8-6.2 is for hydro, soilless mediums NOT soil grows. True soil: 6.3-7.0

Many, many peat mixes are extremely acidic and a simple slurry test with a pH meter will tell you.

Coco may be considered soilless but has a high CEC (Cation Exchange Capacity) - The ability to hold onto nutrients. Thai coco (there are exceptions) is high in Sodium (Na) and potassium,. Needs to be washed and buffered with calcium and magnesium (magnesium nitrate and calcium nitrate) before you plant in it or your plants will always look deficient. KNAAP sells a buffered and washed product that is excellent in 50 liter bags for about bht$610. They are in Surat Thani.

 

With all that said, soil grows rarely need pH monitoring. A true soil grow is incredibly self regulating as long as you maintain adequate runoff. Usually, feed-water-water-feed or feed-water-feed-water, is a good regiment. I have known many, many successful soil growers that NEVER test or modify pH ever. Root exudates maintain pH in the root zone quite effectively.
 

 

[Pouatchee]

Thanks for your input. I currently got my PH to 6.3 -- 6.4 and I ran into a bit of a N deficiency that I remedied today with fish dooo from my fish pond and the plants seem to have benefited rather quickly the leaves were getting smaller and some of the bigger ones were curling at the tips. I monitor my dirt and adjust the PH prior to using it. At first my dirt, which is actually quite good and expensive, had a PH around 7.2 -- 7.4 when I first started using it. Now with a balancing act I got it to a level I like. I will keep reading here when people post and all the comments are registered in my pea brain for future reference. Regards all