Raising soil PH

[Brother Nature]

Hey guys, I've got a bit of a conundrum. I've recently got a new PH Soil meter, gave my plants a test today and my ph is much lower than I'd like. Currently it's sitting at 5.3. The plants seem to be growing totally fine at the moment, but I know there will be issues going into flower. The nutrients I have been using are bio-canna, every other watering (1x-2x a week), ph'd to 6.8-7. The base water has an ec of 0.2 and a ph of 7.3. The soil in use is canna terra pro, mixed with an organic soil specified for cannabis, amended with about a handful of dolomite per 50 liters of soil, and trace elements derived from seaweed. I know I should have done my due dilligence and tested the mix before planting, but I didn't so here we are.

My question is what's the best way to manage this, to up my ph, during a cycle? Can I just flush the girls with a high PH watering, to bring the levels up? Or is there a better way to go about it, been a while since I've grown in soil...

 

[Cerathule]

amended with about a handful of dolomite per 50 liters of soil,

You gotta add something that is high in calcium carbonate and alkaline, in order to neutralize acidity. A lot of these stonemeals can be quite different depending ont the source, but you can find out how it works by putting a discrete amount in clean glass of demineralized water, stirr for 2 minutes, then measure EC + pH.
My own dolomite doesn't do much in that regard but if I use magnesiumlime, at last, the pH raises to 9 and the EC a but. If I stirr more, the EC climbs steadily, slowly, so this would be more suitable to use than dolomite.

 

[Hammerhead]

Lime is what is used to raise soil acidity. If the soil your using has lime, it will continue to buffer to whatever it's at now. It's easier to change to a different medium with a better ph. Roots organic lush has a ph of 6-6.5

 

[St. Phatty]

Wood ash is also very alkaline.

But it is rich in Calcium. I'm not sure what happens if you give a Pot plant to much Calcium.

 

[troutman]

In the future, mix in more Dolomitic limestone into your grow media before planting.
I now add a few drops of pH up and a little potassium silicate along with limestone
to my water to raise the pH.

 

[Mattbho]

Don't go from 5.3 to 6.5 all in 1 shot . Do it gradually. Knock it down a .1 or. 2 per watering.

Are u sure the meter is accurate ?? I would do a slurry test of some of the unused portion . If there's no plants in soil u could just add lime and mix

 

[Brother Nature]

Cheers guys, always helpful to hear other perspectives. Interestingly enough, after getting home and doing another test, the PH has risen .2, sitting at 5.5 now. I did water them last night with water ph'd to 7.8, so I think I may be on the right path with that. I've also done a bit of research and I can get a liquid lime (calcium carbonate) product here that is designed to remedy the very issue I am seeing. So if I can't get things to improve much more by this weekend I'll look into that.

I've got a bit of that soil still mixed up so will play around a bit more with the amendments I have and see if I can get it right. Always pays to have the right tools for a job aye...

Here's the most concerning looking plant, the discoloration on the leaves is what's concerning me..

 

[Hammerhead]

Check your PPM/EC runoff as well. It shouldn't be drastically different than what goes in. If it's super high that will make your medium acidic. No amount of PH adjusting will fix this. A flush will need to be done.

 

[Creeperpark]

Your plant looks beautiful and that's because you have the correct pH. You wrote above the plants seem to be growing totally fine at the moment. That's because the pH is supposed to be low and where it is. The water you're giving the plants has a pH of 7.5 and that equalizes the balance making a healthy pH in your root zone. Don't add a bunch of alkalinity to the root zone because you can lock out major nutrients in flowering. .

 

[Cerathule]

the discoloration on the leaves is what's concerning me..

But it is rich in Calcium. I'm not sure what happens if you give a Pot plant to much Calcium.

It's almost impossible to overdose Ca until internal physiological biochemical pathways break down. Around 800ppm Ca is that border for some plants. But long before, you'll encounter lockout due to ion antagonism, so be aware that too high Ca usually causes a Magnesium-deficiency.

 

[Brother Nature]

Your plant looks beautiful and that's because you have the correct pH. You wrote above the plants seem to be growing totally fine at the moment. That's because the pH is supposed to be low and where it is. The water you're giving the plants has a pH of 7.5 and that equalizes the balance making a healthy pH in your root zone. Don't add a bunch of alkalinity to the root zone because you can lock out major nutrients in flowering. .

Thanks. I’ve been reading up a fair bit in organics and think I have figured out why I’m seeing the low readings and why they’re rising by about .2-.3 per day. I had mixed in my amendments and then planted straight away. My thoughts are being they’re mineral based amendments they need time to break down in the soil to affect its profile, thus your comment and why they aren’t looking deficient makes perfect sense. Other perspectives are always appreciated though. I’m going to continue monitoring and recording my daily ph readings in my grow thread and hopefully things continue the way they are. Thanks for the assistance guys, my end goal is to develop a mix I only need to water and not feed so happy to get as much info as possible along the way.

 

[jackspratt61]

Thanks. I’ve been reading up a fair bit in organics and think I have figured out why I’m seeing the low readings and why they’re rising by about .2-.3 per day. I had mixed in my amendments and then planted straight away. My thoughts are being they’re mineral based amendments they need time to break down in the soil to affect its profile, thus your comment and why they aren’t looking deficient makes perfect sense. Other perspectives are always appreciated though. I’m going to continue monitoring and recording my daily ph readings in my grow thread and hopefully things continue the way they are. Thanks for the assistance guys, my end goal is to develop a mix I only need to water and not feed so happy to get as much info as possible along the way.

Carbonates are your friend in this case. Caco3 will stabilize your ph from swinging. Using different calciums as a feed is good practice. Calcium sulfate,calcium acetate, calcium lactate,calcium nitrate,calcium phosphate...Each one has a different effect. When combined with good biology you'll rarely see any bad effect from antagonisms when using the correct type and amount of calcium as a feed. Remember that calcium and phosphorus balance is job #1 and #2. Look into colloidal phosphate as your p source. Eden blue gold carrys a good product with COA available so you know what you're putting in the mix.

 

[St. Phatty]

Carbonates are interesting - related to their absorption of CO2.

Oman has an important natural resource, ground rock that absorbs CO2 LIKE CRAZY, to make magnesium carbonate, among other things.

Rare Mantle Rocks in Oman Could Sequester Massive Amounts of CO 2

Tests are underway to pull carbon from the air and turn it into minerals belowground

www.scientificamerican.com

 

[Dime]

Lime is what is used to raise soil acidity. If the soil your using has lime, it will continue to buffer to whatever it's at now. It's easier to change to a different medium with a better ph. Roots organic lush has a ph of 6-6.5

Adding lime reduces acidity,I think it has a ph of 13 or something like that,unless you meant it raises alkalinity.

 

[Hammerhead]

Adding lime reduces acidity,I think it has a ph of 13 or something like that,unless you meant it raises alkalinity.

Adding lime increases soil PH. Raising acidic PH is worded correctly. Google can help lol.

 

[Cerathule]

I think it has a ph of 13 or something like that

It's oftentimes different due to the products having no standards. It's basically derived from stone, so when these minerals are taken from different sources, thus will the pH vary. 13 is really high, my own stonepowders here tested around 9-10.

 

[Dime]

It's oftentimes different due to the products having no standards. It's basically derived from stone, so when these minerals are taken from different sources, thus will the pH vary. 13 is really high, my own stonepowders here tested around 9-10.

I think they use it to treat potable water before it enters our homes.

 

[FranJan]

Here's the most concerning looking plant, the discoloration on the leaves......

Top feed with some ready to use compost. A good compost should neutralize any moderate PH swings and green up the plant a bit. Nice plants btw.

 

[Dime]

Cheers guys, always helpful to hear other perspectives. Interestingly enough, after getting home and doing another test, the PH has risen .2, sitting at 5.5 now. I did water them last night with water ph'd to 7.8, so I think I may be on the right path with that. I've also done a bit of research and I can get a liquid lime (calcium carbonate) product here that is designed to remedy the very issue I am seeing. So if I can't get things to improve much more by this weekend I'll look into that.

I've got a bit of that soil still mixed up so will play around a bit more with the amendments I have and see if I can get it right. Always pays to have the right tools for a job aye...

Here's the most concerning looking plant, the discoloration on the leaves is what's concerning me..

You want the ph to change to be gradual so they can deal with it,PH swings are not good. I grow in clay outside and if I do water them I don't check PH,they get used to it, and inside I grow in promix/perlite and never check it and haven't for decades,if I was growing hydroponics I would pay more attention to PH with bare roots. Proper watering is more important.jmo

 

[Creeperpark]

Adding lime reduces acidity,I think it has a ph of 13 or something like that,unless you meant it raises alkalinity.

Lime has a pH of 6.5 and dolomite lime has a pH of 5.5 to 6.5.