best and cheapest way to lower soil ph

[jaredman]

I just got 10 cubic yards of composted manure that I will be mixing with 48 cubic feet of pearlite and 16 cubic feet of coco coir. The ph is at about 8.8 how can I lower the ph and maybe bulk up the amount of soil also? I have 12 raised beds of 4x4x2 so I need 384 cubic feet to fill them I am about 60 cubic feet short right now. Should I just water the dirt with ph adjusted water of like 5 or 4 of should I but some sawdust much appreciated. All info is helpfull

 

[MASSES 420KING]

use dolomite lime powder form and it will at as a ph balancer as well as give calcium and magnesium when needed imho its a staple for the indoor grower and it works just as good outdoors too hope that helps or you can go to your hydro store and by the basic 17 dollar ph test kit

 

[jaredman]

I already have a test meter, a nice one and that is why I am asking the question. Also I thought that lime just stableized the ph so wont that make the ph stay at 8.9?

 

[MASSES 420KING]

I already have a test meter, a nice one and that is why I am asking the question. Also I thought that lime just stableized the ph so wont that make the ph stay at 8.9?

no it should keep it between 6-7 its a great additive i use it and havent had a ph problem since i started using it trust me it works:banana1sv6:

 

[justiceman]

I do not hat dolomite lime is supposed ot have a ph around 7, but I have heard that if you add too much it raises the ph to high? Could be wrong on that one, but since you want to lower the PH I wouldn't add in something that might raise it. I would probably go with garden Gypsum. It is Calcium sulfate and it helps with acidifying soil.

 

[Seamaiden]

To the best of my knowledge dolomitic lime will raise pH, and I know for a fact it can easily bring it up into the 7+/8+ range. Gypsum is another calcareous product, and it 'sweetens' acid soils, not alkaline soils. If you need to acidify add peat.

That said, if you're growing outside organically, my suggestion is to not mess around with it. Just add some actual soil to the mix. The plants will adjust the pH in the root zone themselves, and if you're inoculating with microbes you have even less to worry about.

 

[bobby-o]

gypsum has little to no effect on ph. Gypsum is used to add Ca without raising ph. It is compose of Calcium sulfate.

 

[bobby-o]

ammonium nitrate will provide N an lower you ph so will a sulfur based product.

 

[justiceman]

To the best of my knowledge dolomitic lime will raise pH, and I know for a fact it can easily bring it up into the 7+/8+ range. Gypsum is another calcareous product, and it 'sweetens' acid soils, not alkaline soils. If you need to acidify add peat.

That said, if you're growing outside organically, my suggestion is to not mess around with it. Just add some actual soil to the mix. The plants will adjust the pH in the root zone themselves, and if you're inoculating with microbes you have even less to worry about.

Gypsum indeed contains calcium, but its is Calcium Sulfate and sulfur acidifies soil. It will slightly lower the PH, but if you get soil acidifier from Epsoma it has gypsum and extra elemental sulfur to help with acidification.

Adding peat is certainly another decent idea though.

gypsum has little to no effect on ph. Gypsum is used to add Ca without raising ph. It is compose of Calcium sulfate.

Depending on your mix Gypsum will either lower the PH or at least keep it from raising do to the sulfur content.

ammonium nitrate will provide N an lower you ph so will a sulfur based product.

ammonium nitrate will indeed lower the soil PH, but I believe it is easily dissolved in water(that's why its in ferts) and I might just wash away from your soil at one point affecting the PH. I'd get something that sticks around int he medium, like calcium sulfate(gypsum)

 

[Aquagrow]

Currently running into the same problem in FFOF soil...getting a ph of 7.0 and have been watering/feeding with 6.5 ph. Or should i actually try to match the soil ph of 7.0 to with 7.0 water to avoid ph fluctuation. im confused.

 

[cheyenne]

Dolomite Lime will indeed "sweeten" the soil aka acidify it. Follow the directions on the bag, prob 2 tbs per gal of soil.

 

[MASSES 420KING]

i mix my dolomite at a ratio of 1 1/2 cups to 5 gallons of promix and my ph is around 6.2 6.5

 

[justiceman]

Dolomite Lime will indeed "sweeten" the soil aka acidify it. Follow the directions on the bag, prob 2 tbs per gal of soil.

I was under the impression that when dolomite lime sweetens your soil it mean to raise its PH not lower it.

I used about 1/4 cup and 4 tsp for a mix of 4cubif ft(about 30gal worth) That is the amount the recipe called for. I am starting to wonder whether it was enough since you guys seem to be adding far more dolomite. Mines powdered. Is yours powdered or granulated?

 

[Seamaiden]

I was under the impression that when dolomite lime sweetens your soil it mean to raise its PH not lower it.

That is correct. Because of its calcium and magnesium form and content, it also keeps things buffered (alkaline, as in resistance to pH shift). Interestingly enough, peat can also buffer, but downward.

I used about 1/4 cup and 4 tsp for a mix of 4cubif ft(about 30gal worth) That is the amount the recipe called for. I am starting to wonder whether it was enough since you guys seem to be adding far more dolomite. Mines powdered. Is yours powdered or granulated?

I personally use prilled (pelletized) dolomitic lime. But the more I'm learning about how organic soils work, especially if you're working the 'soil food web', the more I learn that it's ok to mess around with things less, rather than more.

Couple of helpful links.
http://nick.mcn.org/Soil Ph info.htm

2nd link discusses how to acidify soils.
http://www.bachmans.com/Garden-Care...e=02&pageIndex=_pageIndexToken_acidifyingSoil

 

[lil miss lone]

Currently running into the same problem in FFOF soil...getting a ph of 7.0 and have been watering/feeding with 6.5 ph. Or should i actually try to match the soil ph of 7.0 to with 7.0 water to avoid ph fluctuation. im confused.

I was told that to lower your ph in the soil you have to go in with a ph that is 5 points lower than what you want to come out. Example: ph of water/feed going in should be 5.5 if you want to lower the ph of the soil to 6.0.

BTW, I ph to 6.0 for soil. used to ph to 6.2 going in and that caused alot of lock-out, causing a build up, ppms were way out of wack, it was a right mess, but a couple flushes and we are back in bidness.

 

[Aquagrow]

good info cems...giving it a run

 

[SSHZ]

Good thread.......lots of excellent info. Pellitized lime shouldn't be used. Powdered lime is much better because it spreads out better thru the medium. The pellets are heavier and tends to fall lower in the pot. Also, lime takes some time to break down to be useful so pellitized is even slower. I use 3 over-filled cups of lime (also called agricultural lime) per 3.7 cu bale of pro-mix. And another useful tip is: chemical fertilizer is very concentrated in the first 3-4 inches of soil in the pot. If you are having pH issues, CAREFULLY remove the soil from the top of the pot and replace with fresh soil/soiless mix. You'll see the pH of your run off water higher and closer to 7.0.

 

[Zoomzoom]

Currently running into the same problem in FFOF soil...getting a ph of 7.0 and have been watering/feeding with 6.5 ph. Or should i actually try to match the soil ph of 7.0 to with 7.0 water to avoid ph fluctuation. im confused.

Im pretty sure you are on the right track with adding ph 6.5 water, but honestly if it's ph 7 it's not a big problem to begin with, feel free to contact me if you need any advice, I've got a lot of knowledge with biology and I'm aways happy to help.
Happy growing✌