Best practice to lower soil pH?

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testiclees

testiclees

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To lower soil PH??? Not effective in the slightest
Both phosphoric and sulfuric acid lower soil pH when applied appropriately. Are you stating that a few mls isnt enough?
Aluminum sulfate works as a soil acidifier because it forms sulfuric acid when mixed with water.
 
Aqua Man

Aqua Man

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Both phosphoric and sulfuric acid lower soil pH when applied appropriately. Are you stating that a few mls isnt enough?
Aluminum sulfate works as a soil acidifier because it forms sulfuric acid when mixed with water.
Im saying its not enough and it does not have any longevity in the soil. If anything it will cause a reduction and rise effect thats not beneficial. You need a sustained source over time…. Thats aluminum sulphate…. Because it continues to add the necessary acidic influence over time. That cannot be done with sulphuric or phosphoric acid in thise forms
 
Aqua Man

Aqua Man

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Both phosphoric and sulfuric acid lower soil pH when applied appropriately. Are you stating that a few mls isnt enough?
Aluminum sulfate works as a soil acidifier because it forms sulfuric acid when mixed with water.
Read this and if it still doesn’t not make sense let me know. Much like potassium hydroxide will not raise soil PH over any extension time period its to available. Dolomite lime however does and therefore its a good optio to raise soil ph as is aluminum sulphate to lower it

 
testiclees

testiclees

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Read this and if it still doesn’t not make sense let me know. Much like potassium hydroxide will not raise soil PH over any extension time period its to available. Dolomite lime however does and therefore its a good optio to raise soil ph as is aluminum sulphate to lower it

Thanks. I'll check it out.
I dont think id ever deliberately add aluminum to my media or soil in any form. Al doesnt concern you?

I notice that weekly use of sufuric acid stabilized fish hydrolysate through veg tends to drop my soil from ~7pH to about 6.5. But ya thats hitting it weekly
 
Aqua Man

Aqua Man

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Thanks. I'll check it out.
I dont think id ever deliberately add aluminum to my media or soil in any form. Al doesnt concern you?

I notice that weekly use of sufuric acid stabilized fish hydrolysate through veg tends to drop my soil from ~7pH to about 6.5. But ya thats hitting it weekly
That careies a complex answer it can work and it may not work depending on the buffering capacity of the soil makeuo to begin with.

Iron also lower PH thats another option.

The cocern though lays with the nutrient ratios, concentration and its interaction with the soil makeup. The reason this is a slippery slipe is because you solving the oroblem with a risk factor… in this case your resukts cone from increased microbe respiration because of population increase from food and also decay both of which produce co2. Co2 then becomes dissolved in water forming carbonic acid. At a dkh os about 4 around 30ppm od dissolved co2 will produce a ph drop of about 1.0

And the fact that the organics break down produces ammonia/ammonium and when plants take that up they release h+ ions in the process which also lowers soil Ph. Thats right plants can and do actually change soil ph as well as the microbes.

But again that route carries the risk of creating nutrient tox, imbalance in ratios and others.

But also that doesn’t mean it can work. If it works for you then thats all that matters but it doesn’t mean it will work in all scenarios without causing other issues
 
Peat_Phreak

Peat_Phreak

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Lord have mercy. I'm pretty sure Ammonium Sulfate is what you want. Not Aluminum.

Ammonium Sulfate lowers media pH over time. However, if your Nitrate to Ammonium ratio is above 30%, THC will decrease according to science.

Plus this is actual soil here. This calls for some organic crunchy bro advice which I rarely give. OP needs some Lactobacillus Plantarum. That will supply a constant flow of lactic acid ORGANICALLY.
 
SchwiftyGrower

SchwiftyGrower

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Question for curiosity:

Soil pH is 7 and you want to get it to 6.

Can you feed your plants with nutes pH at 5 and level the pH to 6? Or does it not work this way?

I just tried soil for my first time this grow and it never went over 6.5 but I was curious if that approach would work or if it’s counterproductive.
 
R

ritoMox

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Question for curiosity:

Soil pH is 7 and you want to get it to 6.

Can you feed your plants with nutes pH at 5 and level the pH to 6? Or does it not work this way?

I just tried soil for my first time this grow and it never went over 6.5 but I was curious if that approach would work or if it’s counterproductive.
Good question. In my novice ponderings it would seem that mass/volume of soil versus volume of ph solution would decide where the ph of everything lands. Let's see what the pros here tell us✌️
 
Peat_Phreak

Peat_Phreak

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Question for curiosity:

Soil pH is 7 and you want to get it to 6.

Can you feed your plants with nutes pH at 5 and level the pH to 6? Or does it not work this way?

I just tried soil for my first time this grow and it never went over 6.5 but I was curious if that approach would work or if it’s counterproductive.

It can work similar to that way. But it isn't a linear equation. If soil is 7 and you feed 5, the result is not immediately 6. It will be less than 7 and more than 5. It would be very close to 7 with one watering. It works gradually.

If you want it to reduce media pH faster, acid flushing at 4.0 pH works in peat. I haven't tried that with soil. It should work. When the media gets above 7, it takes a considerable amount of acid to reduce it.
 
SchwiftyGrower

SchwiftyGrower

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It can work similar to that way. But it isn't a linear equation. If soil is 7 and you feed 5, the result is not immediately 6. It will be less than 7 and more than 5. It would be very close to 7 with one watering. It works gradually.

If you want it to reduce media pH faster, acid flushing at 4.0 pH works in peat. I haven't tried that with soil. It should work. When the media gets above 7, it takes a considerable amount of acid to reduce it.
Amazing info!! Thank you 😊
 
Aqua Man

Aqua Man

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Lord have mercy. I'm pretty sure Ammonium Sulfate is what you want. Not Aluminum.

Ammonium Sulfate lowers media pH over time. However, if your Nitrate to Ammonium ratio is above 30%, THC will decrease according to science.

Plus this is actual soil here. This calls for some organic crunchy bro advice which I rarely give. OP needs some Lactobacillus Plantarum. That will supply a constant flow of lactic acid ORGANICALLY.
Nope i meant aluminum sulphate… But there are many ways to lower soil Ph. That bacteria is much less effective.

just a question here because the oeganic religion is full of half truths but so is everything else cannabis related. Im not saying organics is not good but it’s extremely misrepresented. You do know a mineral salt is simply a scientific name and not salt as in sodium. You do know that plants cannot uptake organic nutrients?
 
Peat_Phreak

Peat_Phreak

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The reason to avoid using Aluminum Sulfate is cannabis accumulates Aluminum. Smoking aluminum is something we should be limiting, not increasing. Especially when there are safer ways to reduce media pH. Of course there is some science to back up my claims.

 
Aqua Man

Aqua Man

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The reason to avoid using Aluminum Sulfate is cannabis accumulates Aluminum. Smoking aluminum is something we should be limiting, not increasing. Especially when there are safer ways to reduce media pH. Of course there is some science to back up my claims.

Yeah i get that and fair point. But the devil is in the dose… Aluminum is abundant in soil and especially can be high along with other metals in organic fertilizer. Its also a bio stimulant and has its own benefts. True high amounts can be harmful but that no different than anything else.

take rice for example its very high in arsenic… its good for you in moderation but we should be mindful. To much of anything is not good but that doesn’t mean its not beneficial
 
Peat_Phreak

Peat_Phreak

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And just to clarify the use of Ammonium Sulfate. It's not good to use in the beginning of the grow when the soil is loaded with raw nutes. Ammonium Sulfate adds N and S.

So if I ever bought soil (never gonna happen) that was 7.8 pH before planting, I would do an extensive acid flush with citric acid. It does not affect NPK or deposit metal into lungs. Then I would inoculate with lactobacillus for long term gradual acid production within the media.

There are many ways to inoculate with lacto, but most lacto is ill suited to ferment at 70-80F. That's why I would skip the crunchy bro approved "banana peel lacto ferment" or similar concoction and buy some lactobacillus plantarum which works well in the 70-80F range.
 
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