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PH levels

CC420710

Active Member
Hey everyone just me with my millions of questions. This forum has been more useful to me than all the research I've done so this is one of the first places I turn now. Anyway on to the subject of ph. Just wondering what things might lower or raise it? Mostly in the aspect of things we use commonly like nutrients. I know nitrogen I believe lowers it? Phosphorus and potassium Idk the effects there. Then there are other things depending on the person. Cal-mag, epson salt ect. I know dolomite lime is supposed to help keep neutral though there is a lot of confusing info out there that says it lowers the ph. Just trying to get an idea of what would cause the ph to rise in my plants? Also, neem oil and I use fox farm trio, golden tree, and kelp normally. Had to use alot of neem recently. I know to do the water first and make sure it has correct ph which; plays a big part just wanted to go over any other common causes,
 

Gshoo

Member
Hey man, from my short experience I can say that Cal-mag doesn’t affect the acidity. The water from my sink usually is about 7.3, when I put all of the nutrients it drops to 5.8. I guess this depends on the nutrients you use. Different brands will have different effect on the water. Before I used to measure and fix the water from the sink, before adding anything to is and my plants started having issues. Now I always check after I add the nutes.
 

Weaselcracker

Nug of the Year: 2016 - Member of the Month: Sept 2015, Nov 2016 - Nug of the Month: Oct 2016 - Plant of the Month: May 2016
Any good organic soil should have a decent ph level, as well as a fair amount of ph buffering ability, meaning its basic ph shouldn't be permanently changed by feedings and you shouldn’t need to worry much what the ph of your feedings are. The lime, clay, and minerals in organic soil do a good job of maintaining soil ph where it should be.

Hydroponic grows often use mediums that are basically just there to hold roots and whatever nutrients you wash through them. Examples are rockwool, coco, clay pebbles (hydroton), perlite, peat moss, etc. These mediums do not contain nutrients other than what you add, and don’t have much/any ph buffering ability. So with a hydroponic style grow, ph levels of the nutrient mix have to be monitored and adjusted for every feeding.

Almost all bottled nutrients are acidic.
 
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CC420710

Active Member
I used a lot of peat because it’s supposed to be neutral or lower, black gold organic soil, vermiculite and perlite. So it would have to be something I added right? Assuming the water would be the only thing that really affects it? I definitely need a new pen as these strips aren’t helping enough. If I’m wrong in any of this feel free to correct me? I know next time to put in dolomite from get go? I want to try coco fibers at some point. Any other amendments anyone uses to balance it out? I just wanna make sure to not make same mistakes as first time
 

Bush Doctor 77

Well-Known Member
I used a lot of peat because it’s supposed to be neutral or lower, black gold organic soil, vermiculite and perlite. So it would have to be something I added right? Assuming the water would be the only thing that really affects it? I definitely need a new pen as these strips aren’t helping enough. If I’m wrong in any of this feel free to correct me? I know next time to put in dolomite from get go? I want to try coco fibers at some point. Any other amendments anyone uses to balance it out? I just wanna make sure to not make same mistakes as first time
Peat is acidic and between 3.5 and 5 pH. That's why it's peat. It's vegitable matter preserved in an anaerobic acidic environment.
 

Emilya

Member of the Month: Mar 2019
Commercial Potting soil is usually buffered at 2 points in the pH chart. Peat is used because it will break down when it encounters high pH liquids and will try to neutralize them or at least bring them up into a higher place in the chart. Peat is acidic and is your high end buffer.
Soils also oftentimes add dolomite lime, which being high in pH, will react to water that comes in closer to the acidic side. The lime will tend to neutralize out the acids and is your low end buffer. Usually more lime is added than peat, so that the overall balance or the base pH of your soil mix is at the high end of the usable range, near 6.7-6.8 pH.
Synthetic nutrients are locked up for storage and transport in chemical salt bonds that are designed to break apart when the pH of the solution they find themselves in reaches a certain pH range. Some of the individual nutrients are more easily taken up into the plant at different pH levels than others, so we have found that it is desirable to allow our pH to "drift" between the low to the high end of the pH range, so as to allow each element to have its own optimum pH to work with at some point during the course of the normal wet/dry cycle. Soil is generally more heavily buffered at the high end, so that if we water at the low end, at 6.3pH, the soil will force the nutrient solution suspended in there to slowly drift upwards through the range of 6.2-6.8pH. Most commercial soil needs no additional adjustment to make this happen. If you are mixing your own however, and have added the peat, but no dolomite, then your soil would not cause an upward drift, it might actually drift the opposite way. Knowing what you are dealing with as a base pH of your soil mix is very important, and will determine what the correct pH is that you need to be coming in with as well as the type of nutes you want to buy.
 

CC420710

Active Member
Peat is acidic and between 3.5 and 5 pH. That's why it's peat. It's vegitable matter preserved in an anaerobic acidic environment.
That's the main reason I chose it in hopes to avoid ph issues. Any test that works best for finding out ph of soil? I have tried many things but my digital 3 in 1 isn't very accurate. I have used the capsule tests a few times and of course, strips which don't work in soil except runoff. So far I think the capsules are the most accurate other than a ph pen
 

Weaselcracker

Nug of the Year: 2016 - Member of the Month: Sept 2015, Nov 2016 - Nug of the Month: Oct 2016 - Plant of the Month: May 2016
Peat in any sort of growing application usually has lime added to bring the ph higher. Maybe yours does too?

Commercial peat based mixes like promix and sunshine mix definitely add lime. The people at Sungro are very helpful and will be happy talk your ear off about the subject if you contact them. Here is an article about peat and ph. Harmonizing Peat and Lime - Sun Gro Horticulture

I’ve talked on the phone to the fellow who wrote that article, a couple times now, and he seems ever eager to chat about peat moss with random idiots like me.

You will need a better ph testing method before getting concerned over it. The strips can work ok. The ‘3in 1 meter’ is crap if it’s the type I’m thinking of. Just make sure you’re doing a proper slurry test and not just grabbing some random runoff from the pot
 
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Emilya

Member of the Month: Mar 2019
This is all good info but I am still a little confused about this mix that you are calling soil. If it is mostly peat, then you are not growing in soil at all, and your pH needs to be changed on all of your inputs to the hydro range of things. If you have a soil/peat mix it is important to know how much of each is in there, so we can advise accordingly.
 

Bush Doctor 77

Well-Known Member
I live surrounded by peat bog. I keep meaning to go dig around off the end of my driveway and grab a truckload, maybe this conversation will be my final push :laugh2:
You could bury it a few miles deep, wait 300 million years and you'll have coal.
 

CC420710

Active Member
Commercial Potting soil is usually buffered at 2 points in the pH chart. Peat is used because it will break down when it encounters high pH liquids and will try to neutralize them or at least bring them up into a higher place in the chart. Peat is acidic and is your high end buffer.
Soils also oftentimes add dolomite lime, which being high in pH, will react to water that comes in closer to the acidic side. The lime will tend to neutralize out the acids and is your low end buffer. Usually more lime is added than peat, so that the overall balance or the base pH of your soil mix is at the high end of the usable range, near 6.7-6.8 pH.
Synthetic nutrients are locked up for storage and transport in chemical salt bonds that are designed to break apart when the pH of the solution they find themselves in reaches a certain pH range. Some of the individual nutrients are more easily taken up into the plant at different pH levels than others, so we have found that it is desirable to allow our pH to "drift" between the low to the high end of the pH range, so as to allow each element to have its own optimum pH to work with at some point during the course of the normal wet/dry cycle. Soil is generally more heavily buffered at the high end, so that if we water at the low end, at 6.3pH, the soil will force the nutrient solution suspended in there to slowly drift upwards through the range of 6.2-6.8pH. Most commercial soil needs no additional adjustment to make this happen. If you are mixing your own however, and have added the peat, but no dolomite, then your soil would not cause an upward drift, it might actually drift the opposite way. Knowing what you are dealing with as a base pH of your soil mix is very important, and will determine what the correct pH is that you need to be coming in with as well as the type of nutes you want to buy.
So that leaves me to believe that my water is the problem then. Though I don't understand why the water would change? I know I need a new pen as the strips aren't the most accurate or at least I hope that's the problem
 

TorturedSoul

Member of the Month: May 2009, Oct 2010, Sept 2017
So that leaves me to believe that my water is the problem then.
Are you implying that your medium isn't mostly (or at least substantially) peat moss, then?
 

CC420710

Active Member
Are you implying that your medium isn't mostly (or at least substantially) peat moss, then?
No, the opposite it is at least 50% peat. That's why I am struggling to why it's running on the high side or is it just my measurement tools being inaccurate? New pen coming for water check and I'm guessing get some more capsule test unless someone knows anything more accurate?
 
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