@krnuttle How about we start with at least one fact concerning a real adjustment. Set aside buffering issues. If I start with soil that is pH 4.5, and I add dolomite lime at one tablespoon per gallon of soil, what target pH should I get, after the chemistry has settled down in a month?

So how many tablespoons is that? Is that 1 TBsp to raise the PH from 4.5 to 5.5 (for example)...but 10 TBsp to raise it from 4.5 to 6.5. ? i got confused ...sorry -I almost flunked chemistry -lol- and now you know I should have! And how often would you have to add it?

You can not separate the buffering issues from the measurement of the pH,

@Gargamel I don't know. That's why I asked the question. :)

@krnuttle So then why are we all adding one tablespoon of dolomite lime to each gallon of soil? Your position is we can't understand what that will do.

You could make assumptions about buffering and answer the question.

You're adding 1 Tablespoon of Dolomitic Lime to a 70% bark mix to raise the pH 1 point on the pH scale. That's why you're adding the Lime. It's really not more complicated than that.

What do you think will happen if you double the Lime? Do you think the pH will jump 3 points, 5 points?

Josh

@greenman28 NorCal 7b/8a Let me frame this question differently. Let's agree that one tablespoon of dolomite lime takes you up one point on the pH scale. In that case, how many tablespoons take you up by TWO points on the pH scale? Keeping in mind that this is NOT a linear problem, two points on the pH scale means 100 times increase in alkalinity not 10 times increase. It looks like answering that question is not as straightforward as I would like.

I also think it is much more complicated than even your summary that one tablespoon equals one point of pH shift. I think the advice to add one tablespoon is built on a set of assumptions:

* The starting pH is assumed to be something specific.

* The buffering characteristics of the soil are assumed to be something specific.

If the advice was built on the assumption that you start at 5.5 and want to end up at 6.5, and the soil is a bark/peat mix of specific composition, then the question becomes how much to add to go from 4.5 to 5.5. Where you start on the pH scale looks like it very much affects the answer. The amount of lime that adjusts 4.5 to 5.5 might be very different than the amount that adjusts 5.5 to 6.5. Both of those are one-point pH shifts, but they imply dramatically different amounts of alkalinity at the starting point.

If one tablespoon of dolomite lime takes alkalinity up ten times - and please remember that going up ten times is ONE point on the pH scale - then logically adding two tablespoons would take you up 20 times. A 20 times increase in pH is approximately a jump in pH from 4.5 to 5.8.

So this looks to be far from a trivial problem, and the common wisdom of one tablespoon per gallon of soil looks like it was built for one very specific problem: how do we adjust the 5-1-1 mix.

Adjusting the 5-1-1 mix is not the problem I want to solve at all. I make a wide range of custom soil mixes, and I need to understand this issue at a much deeper level and in a much more general way.

It would be hard to advance this question further until we understand what are the assumptions behind the current advice of one tablespoon of dolomite lime = 1 point of pH shift. @tapla (mid-Michigan, USDA z5b-6a) may be the only person who can answer that.

Oh, I assumed we were talking 5-1-1 mix.

Yes, Lime will change a bucket of gravel differently than a bucket of bark.

Hopefully Al will be able to offer some advice.

Josh

@greenman28 NorCal 7b/8a But even if we limit discussion to 5-1-1 mix, I suspect the amount of lime required to shift pH from 4.5 to 5.5 is very different than the amount required to shift from 5.5 to 6.5. Both of those are one-point pH shifts.

I think it would be roughly 1 Tablespoon in either situation. I don't think it would be a very different amount at all.

If I had the time, I would just make a batch of 511, test the pH, split it into a few containers, and do a test.

Josh

@greenman28 NorCal 7b/8a Dolomite lime itself buffers pH, and there are so many buffers in the soil that I am sure that makes things more complicated. But look at the table below showing what pH actually measures. It looks like pH acidity is largely a measure of the activity of hydrogen ions (H+). Only they invert one divided by 10 to the power of pH to derive the amount of H+ Activity.

To look at an extreme case, a pH of 1 seems to imply about 10% hydrogen ion activity in the solution. A pH of 4 implies about 1 / 10,000 H+ activity. A pH of 5 implies 1 / 100,000 H+ activity. A pH of 6 implies 1 / 1,000,000 H+ activity. Less hydrogen ion activity = less acidity.

Assume - using your statements - that one tablespoon of dolomite lime could take you one step higher in pH no matter what pH you start at. In that case, one tablespoon of lime can take your soil from pH 4 to pH 5, thereby diluting H+ activity by 1 / 90,000 hydrogen ions (10K + 90K = 100K). Now consider going from pH 5 to 6. How can that same one tablespoon of lime this time dilute the solution by 1 / 900,000 hydrogen ions (100K + 900K = 1M)? The same one tablespoon of lime only dilutes 1 / 90,000 ions in one case and suddenly becomes 10 times less potent and neutralizes only 1 / 900,000 ions in the next one-point jump up in pH?

I am not saying you are wrong in your conclusion. I am saying this looks like a highly non-trivial problem and what you are saying doesn't make much sense to me, at least yet.

It us too bad our school teach self esteem instead of Chemistry.

Thanks, that makes much sense. Interesting to see the "limit" of the Lime's ability to adjust beyond 6.5 or so.

Josh

Excellent post kevin9408 !

As a chemist: This is a VERY non-trivial problem for all the reasons stated.

Not the least of which is the type of bark or other organic material used. I would opt for the 'trial and error' approach myself.

@krnuttle this a problem even college students taking soil chemistry would scratch their heads over. I don't think our education system is to blame for this one.

BTW I actually took a soil chemistry class in grad school. We had to write a program to calculate the concentrations of a bunch of ions in soil pore water. But the concentration of each depended on the concentrations of all the others (in addition to various other factors that also had to be taken into account). So the program had to 'iterate', i.e. plug the results in as starting values and recalculate over and over to approximate the true answer. It was not trivial at all.

Chemistry students would understand the parameters and realize there is NO simple solution to calculate the lime.

True. They would then scratch their heads if you insisted on an actual answer as is required in many practical situations like this thread!

@outpaientzero I would not say I am looking for an easy answer. I am looking for sufficient depth to be able to move a peat/bark soil mix from any starting pH to a pH around 6 to 6.5. If we want to simplify the problem, then how about we take a peat/bark soil with three starting pH values: 4.5, 5.0, and 5.5. How much Dolomite lime in each of those mixes would get the pH to around 6 to 6.5? Is the answer different for peat alone than for bark alone?

If what you say is true, and it only takes 20% more lime to go from 5.5 to 6.5 than from 4.5 to 5, then that is probably not worth worrying about. I might tend to err on the high side though since an "overdose" of lime appears to have a benign effect. So if I calculate I need 2.2 tablespoons, maybe I add three instead.

@toxcrusadr And your post exactly explains why the first sentence of the original question was "Is there an online calculator...." This is exactly the kind of problem that you want automation to help solve. Some set of starting assumptions could be made fixed, and others could be made variable. But if a human being can solve those equations - even if they involve some kind of iterative approach - a computer can solve them too.

At the end of this thread, we may end up concluding that - for a typical peat/bark soil mix - moving pH from anything above 4 to 6.5 can be done on a one tablespoon lime = one pH point basis. The actual reasons why that works might be complicated, but for practical purposes it might be sufficient.

The good news is that using dolomite lime for the adjustment tends to have a limit on pH adjustment to around 6.5, which is exactly where we want to go anyway. So adding a bit too much might be a good strategy.

So, pretty much exactly what I said :-)

Glad to know I've been doing it right this whole time.

Josh

@greenman28 NorCal 7b/8a But not for the reasons you suggested it. There is probably not a general "1 tablespoon per one-point rise in pH", but it appears to just work out that way when going from pH 4.5 to 6.5, The fact that too much lime will not raise pH above 6.5 greatly simplifies everything and largely de-risks the whole process.

It would still be great to read what @tapla (mid-Michigan, USDA z5b-6a) used as his reference points for that guideline.

>>The good news is that using dolomite lime for the adjustment tends to have a limit on pH adjustment to around 6.5,

I was not that familiar with dolomitic lime, but that does appear to be the case. Limestone (calcium carbonate) tends to settle around 8-8.3 I believe, which is the carbonate/bicarbonate buffer pH. If I had known this little factoid earlier in the thread I would have said the same thing. The only time you'd have to be super careful is if you were trying to settle somewhere in between.

Westes, I took the liberty to source the PH range for dolomite lime with somewhat surprised, nothing was consistent and higher than you stated. These numbers are from the Safety Data Sheets (SDS) of the dolomite the companies mined or sourced.

8.5-9.5 at 10% solids. Dunn construction co.

7-9. DMI diversified materials

9.4. National lime and stone

I don't know what site your information came from but misinformation was the initial reason I started finding multiple sources of qualified and educated professionals with real expertise to source, and not just a website. Goodhousekeeping, Msgardener, leafy ect.......forget it.

I was just passing on what I felt was a creditable source related to dolomite related to pine bark substrates, and I was also surprised with their conclusion ("there will be very little increase in PH no matter how much more dolomite lime in added") and wouldn't go excessive with the lime unless proved they were right. Give it a test, take a gallon of your pine bark mixture and add 3 tablespoons or more without plants and see what happens.

I mentioned using a split of dolomite and calcitic lime for good reason. Lime will be your base to neutralize acidity, it will soak up H ions and turn the Mg and Ca carbonate into water soluble bicarbonates which will leach out, The bicarbonates will also degrade into carbolic acid, and finally degrade into CO2 and H20 until it's used up. In the mean time the organic substrates will continue to decompose further and release organic acids which will lower the PH over time. Most dolomite is finely ground to dust and designed to work fast and only last a few months based on mesh size. Other limes work slower and have various mesh sized particles in the mix to prolong the neutralizing effect for much longer periods. Pro mix uses this approach when they add lime, greenhouse nurseries just use dolomite for faster results and long enough the plants out the door.

@outpaientzero What I had read was that the gardening variety of dolomite lime is "uncooked" (I have no idea what that means) and is pH neutral. This is in contrast to the dolomite lime varieties using in construction and other applications that are apparently extremely alkaline. Since your sources for pH measurement are construction material supply companies that much seems to match up. Presumably, there must be some chemical difference between different types of dolomite lime, and I was unable to clarify further. Maybe your references will enlighten us.

The empirical workaround for the variance you found is to test what you use. I mixed Espoma dolomite lime with neutral water and ended up testing pH at 6.6. If I bought a dolomite lime that tested as much higher than pH 7 I would not use it.

Assuming you are right and dolomite lime can have a pH > 8, I would like to know how it is the study previously cited is able to conclude that dolomite lime adjusts pH no higher than about 6.5 regardless of how much is used. The more I learn about this topic the more complicated it becomes.

I would hassle with mixing different forms of lime if I were selling a commercial product. But I am just a home gardener trying to do something that fairly bombproof while making it very easy to implement. The point you make on duration is important, and that is disappointing if these dolomite lime treatments wear off so quickly. I noticed that Espoma dolomite lime has a wide variety of particle sizes. Maybe this is their attempt to address this issue. But it Is an important point because if you open a bag of dolomite lime and it is all a fine powder, that would make your point about a short lifespan very relevant. I guess we need to look for lime mixes that have plenty of large particles that will slowly break down.

All lime will vary from one source to another and aren't standard to one set PH. It's because the amounts of the minerals in the lime are never the same from one source to another. On many bags of lime there will a second number for calcium carbonate included with the chemical analysis of the product. The second number for calcium carbonate will have the abbreviation CCE after it. It refers to the effective neutralizing ability of their lime compared to an industry standard. The number in percentage will be high, in the 80's and 90's, this percentage tells how good it is compared to the standard based of 100%.

I can't give any specific knowledge on container gardening because I don't do it and know little, but liming is a standard subject. Now others here do container gardening with many years dedicated to the practice and have the knowledge. I've learned my lesson not to argue with people who know what they're doing when I don't, but think I do, it burns bridges. I lurk to learn here because I plan to try container gardening in the near future and may need advice going forward.

Here's a thread on pine bark 5yrs ago and I read it today. Pine bark I learned something from this thread and if you read it pay special attention to @gardengal48 (PNW Z8/9 comments. Something new to me and very well presented. I've had my rounds with her but my know-it-all arrogance burned a bridge.

@outpaientzero Well you have made me aware now that dolomite lime targeted to construction activities is much more alkaline. And - for whatever reasons - the dolomite lime sold into gardening activities seems to be at a pH near 7. That actually answers another thread I posted here about a mason's dolomite lime I found that was not answered, and thank you. Given the variance among dolomite limes, I know now to always test a new bag before I use it. Having a pH around 7 might help protect me from accidents where too much dolomite lime is applied.

I have learned a huge amount from @gardengal48 (PNW Z8/9) and her generous sharing of information. In this thread, I simply asked that I be allowed to put on my scientist and engineer thinking cap and try to understand the science behind common wisdoms. It is totally okay if others do not find that topic interesting. There is more than enough validation by others in this thread to show that the question I am asking points to a real complexity in the topic.

I was not aware dolomite lime was used in concrete, but regular calcium lime is too, and in roasted form it is Ca and Mg oxides (instead of carbonates) which are extremely alkaline. There is also 'ag lime' which is the same highly concentrated stuff.

In fact we encourage people who are getting manure from barn cleanings to ask the owners/donors if they use lime to reduce odors in the barn. This can throw the pH of the manure/bedding very high.

@toxcrusadr Here is a lime that is labeled as a mason's lime on the package and sold as dolomite lime by the retailer.. I found multiple published studies looking at dolomite lime for concrete strength. I don't know how common it is with concrete, but I see it used for mortar and stucco commonly.

Can you explain what is the "cooking/roasting" process that is applied to raw dolomite lime to develop the roasted form? Are they adding in additional chemicals or minerals in that process, or does the roasting alone transform the raw dolomite lime into a form with higher alkalinity?

Since @tapla (mid-Michigan, USDA z5b-6a) is not in this thread (yet), I searched out some of his old threads and saw this interesting comment buried in the comments section:

"For reference, 5:1:1 made with pine or fir bark would require about 1 u.s. tbsp lime per gallon of substrate (3.5ml/L), or 1/2 cup per cu ft (about 105ml/30L). You can make your own conversion table based on 3.5 ml/L. Keep in mind that 5 units of bark + 1 unit each of peat and perlite does not = 7 units of substrate. Count the units of bark as full units of volume and the peat/perlite as half units to come up with the approximate volume of the end product; this, because the product occupying space between the bark particles does not increase the volume. Think of a liter jar filled completely with marbles - you can add about 300 ml of sand to it w/o increasing the volume or overflowing the jar."

What confuses me about the above is why does Al count peat and perlite as half units of volume? Since peat has smaller particles and less air space, it is contributing more to the volume than the equivalent amount of bark. Using his "do not count air space as part of the volume" approach, it would be the bark that gets adjusted units, not peat? But he has it reversed from that. Why? And why does perlite get any adjustment in his formula at all? Pumice and perlite are volcanic rocks and should be pH neutral?

I believe the cooking referred to is the heating of calcium carbonate to create calcium oxide (removing the co2). In pure form the output is basically quicklime, caustic and reactive.

I presume that cooking most calcium compounds might do this in various degrees and that often then used in intermediate compounds and sold in more stable forms, not selling usually as pure quicklime.

And as I understand for the use as a binding agent (construction) cooked ie eactive forms are needed.

@westes Zone 9b California SF Bay unless I'm misunderstanding that comment from Al, I take it that Al is simply talking about the measure of the volume of mix - not necessarily talking about the pH of the pumice or perlite. When I'm making 511 mix, I thoroughly incorporate the ingredients, then calculate the volume, before adding the Dolomitic Lime.

Josh

@armoured So that raises the possibility that uncooked dolomite lime always has a pH near 7, and the forms of dolomite lime with higher pH are always the cooked form. Is there any reference that will prove or disprove that? This would help to resolve the discrepancy between the pH 7 references I found and the ones that @outpaientzero reported in data sheets from construction supply companies.

@greenman28 NorCal 7b/8a Al is calculating the amount of lime to add to a seven-part mix as if it has only six parts. So he made adjustments to the actual volume and I am trying to clarify his rules for doing so.

Let's use an example that might raise this issue in a clearer way. What if you had a soil mix that was one part peat, one part bark, two parts turface, and two parts pumice. I am not saying that mix is good or bad. I understand why container purists will hate peat in most container mixes. Let's sidestep all of that. In terms of just pH adjustment, how would Al apply his rules to this mix to determine the amount of dolomite lime to add, to get pH near 6.5?

Would Al take the volume of just the peat and bark and calculate one tablespoon of dolomite lime per gallon of peat and bark in the mix? That would be easy to understand and implement. But it does not seem like the exact formula he used. I don't understand why we would want to include pumice or Turface in the volume calculation since those are pH neutral and do not require adjustment.

Edit for clarity: I'm talking about 5-1-1 mix below.

We're basically ignoring the small fraction of binder and perlite/turface/pumice, et cetera. Those ingredients end up "fitting" between the bark, and not significantly increasing the volume of the mix when added to the container.

I can't speak for Al, but if you wanted to adjust your bark-based mix, you could probably just add the Dolomitic Lime based on the amount of bark being used and ignore the grit entirely.

To go further, many of us use a quality peat-based potting mix as our binder (rather than straight peat), and many of these potting mixes are already pH adjusted or include Lime. So that small portion really doesn't matter much anyway.

Josh

I cannot speak for Al but would suggest you're overthinking this - his dosage was based on final volume (I presume experimentally ie that's what he found works for him) and his warning is that final volume is not equal to the volume of the parts.

And I'm sorry I can't answer the question about exactly which form of 'lime' (liming agents including dolomite) may be cooked/uncooked. To me there's a bewildering variety of different compounds used for different uses, was just explaining the 'cooked' (terminology also varies) vs non-cooked naming. To keep it simple seems best for your uses to stick to regular dolomitic lime - safer and available and a known quantity.

One other point - a lot of the information about liming is for agricultural purposes - ie in a field and not in containers - and quite different set of issues (more controlled environment in the latter). "Once and done" to get the acidity in normal range probably is enough unless water being used is quite acidic. Farmers will want an agent like limestone that's longer lasting. Even for a container though the best most simple method is likely experimentation.

But I warn I'm not a container grower, and not a chemist.

@armoured It's fine to just follow Al's guideline if your whole world is 5-1-1 mix. I never use 5-1-1. So I have to think about it because no one has packaged the information for the soils I mix in a way that does not require some thinking.

Answering a question a few posts up - caustic and reactive here means very alkaline. Since the uncooked is not so caustic, yes, I'd presume it's close to neutral. I understand eg quicklime will react to co2 in the air, reversing the process. If I understood the question.

@armoured That would resolve the different facts about dolomite lime pH that @outpaientzero and I had each located. The data sheets he is seeing with pH >= 8 are probably all cooked lime. The blogs and other non-reference-quality posts I am seeing that claim dolomite lime must be close to neutral are probably referring to uncooked dolomite lime. For obvious reasons, gardening consumer-focused dolomite lime products are probably mostly the uncooked variety, but you can and should test for that when you buy a bag. The ambitious might want to mix different types of lime together, but personally, I want something that is easy to buy, understand, and implement, without a lot of testing and experimenting around lime mixes.

I'm not clear from above by kevin9408 whether it's a reference to dolomite lime or various other types of lime, but to approach a different way - he references limes sold for construction purposes (it looks like anyway), and for those purposes it would need to be reactive (in order to work for mortar prep and similar uses). I can't say that confirms it's been cooked or not. That said he mentions a labelling standard so if that's there, do refer to that for the reactivity . But if you're buying garden store Dolomite lime powder, I'd guess usually closer to neutral and less reactive (alkaline).

Side note: you asked in a separate thread about mason's lime - same conclusion as above. If you go to that producer's website (graymont) they produce agricultural and construction products, almost certainly from the same mines/quarries. The mason's lime products refer clearly to calcium oxide and calcium hydroxide; the agricultural dolomitic lime datasheet says calcium carbonate (and magnesium carbonate).

Their quicklime page says "Quicklime is produced by heating limestone as shown in the following equation: CaCO3 + HEAT = CaO + CO2".

https://www.graymont.com/en/products/quicklime/high-calcium-quicklime

Similar explainer for dry calcium hydroxide: "hydrated lime Ca(OH)2 is a dry powder produced by combining quicklime with a sufficient amount of water to satisfy the quicklime's natural affinity for moisture. The process converts CaO to Ca(OH)2."

So this is pretty clearly the same point I was making, that what you're getting should be on the package (terminology might differ unfortunately) - the CaO is from the cooking.

Now a warning: this is not the same thing as soil chemistry - like volume of different substances is not just simply additive, I don't believe you can just simply add up the pH of various components to get your answer either. It's not in a vacuum chamber, it will react with air and water and other components (and release some as well), and I'm not going to try to guess at how the end result comes out. (As noted, quicklime will react with air to make calcium carbonate, for example).

I think only experimentation will be reliable in practical terms for your uses. A simple 'adding stuff that's neutral/somewhat basic will tend to make it less acidic' is true but not very specific in terms of dosage.

I'd also note that organic components of soil / compost will tend to neutral over time too (with possible warning that water varies in acidity and fertilizer additives may have some effect too).

@armoured That was a great summary and I bookmarked it.

As I said several times already, I would not mix limes. For my own use, I will select an agricultural dolomite lime and measure that it has a neutral pH around 7. Then I can feel a little safer in the effects of a calculation error and applying too much lime.

I remember years ago reading on pot forums, when I frequented those, that dolomite lime itself buffers the soil. So for illustrative purposes, let's say 1 tbsp lime might be more than you need to get to 6.5, but the remainder of the DL will sit there waiting for the solution pH (of the soil, water, etc) to dip below 6.5 so that more of the DL can react and raise pH.

I'm certainly no expert. I hope someone more intelligent will chime in. I'm going to explain how I understand things, but I'm not asserting that what I'm saying is true. Rather I'm trying to point someone more capable of research than me into what might be the right direction.

I don't think garden DL is 7 pH. I think it's higher than that at least 8. From what Kevin posted:

"Using sourced data they demonstrate that Dolomite lime (DL) can change the PH up to 6.5 and at this point the PH limits dolomite solubility and thus limits subsequent increases in PH. They go on to say once the PH of 6.5 is reached there will be very little increase in PH no matter how much more dolomite lime in added, so it's kind of hard to overdose a container with DL. "

Thats not saying the DL is itself just above 6.5 pH, it's saying that regardless of how much DL you add, it only raises the solution pH up to 6.5 as past that, the DL becomes locked out. Like nutrients get locked out if pH is too low or too high. The DL increases the pH until it locks itself out. This is how it buffers pH

From the study Kevin linked

@Jonah Henry - you have a point and an implied question I can't answer - you wrote "I don't think garden DL is 7 pH. I think it's higher than that at least 8."

The one bit that jumped back into my head just now is that pH is defined as the concentration of hydrogen ions in a solution - in other words, it doesn't generally make sense to talk about the pH of a solid, like powdered dolomite lime. (You can find colourful analogies about this, eg pH of a solid makes as much sense as the length of a liquid...)

So I think that if DL isn't / doesn't tend to be soluble above 6.5, as your texts refer to, perhaps it would be fair to say it's not relevant what the hypothetical pH is - save that the hypothetical or latent higher pH might be the buffering capacity you referred to, but doesn't mean it will become alkaline with excess DL.

That said, I know enough chemistry to know this is way above my knowledge level and there are probably a million different ways my phrasing of this is wrong. Relevant here, for example, that highly reactive powders may not have a pH per se (because solids) but doesn't mean they won't react to (go into solution in) air or moisture in air or water of any kind that they contact. Or more generally that how / when they'll be soluble is not a simple question.

(And that's before even asking the question about gases or solids that act like liquids in certain respects/conditions but let's hope eg supercritical steam or magma are not conditions one will encounter in container gardening).

I'm not certain but I think years ago, out of curiosity, I put some dolomite lime into R.O. water, shook it up, and tested the ph using General Hydroponics' pH drops, I want to say it was close to 8.5.

I would test it again now but I don't have R.O. water and my tap water is already 8.

I could ph down some water to 7, then add the DL but it wouldn't be the same.

I remember reading something about how distilled water, can be more affected by the pH of something than acidic or alkaline water. I think the idea was distilled water doesn't have anything in it affecting the pH yet so there's nothing to compete against. I guess that means nothing with buffering effects.

So DL in distilled/R.O. water might give a higher pH reading than DL in tap water that's been pH adjusted. Or in solution with the soil etc.

@Jonah Henry Kevin's sources were all from construction products companies, and based on the further discussion here it looks like those might have been "cooked" versions of lime that are highly alkaline. Confining to agricultural-focused dolomite lime products, it appears that most of those have close to a neutral pH. In any case, those are the only products I want to use, and I plan to test the pH and reject products with pH greater than 7.

When testing pH, of course you always want to use distilled water, to establish a neutral pH and prevent chemical reactions with anything in the water.

To avoid any confusion westes the products I listed are for Dolomite Limestone. They're not cooked and are not quick lime. If they were the Substance or component would state Calcium Oxide (CaO) or Calcium Hydroxide (Ca(OH)2).

PH 8.5-9.5 at 10% solids. Dunn construction co. Substance : Calcium Carbonate. Source Dolomite SDS from the company.

PH 7-9. DMI diversified materials. Component': Calcium carbonate/dolomite. Source-Dolomite SDS from the company.

PH 9.4. National lime and stone. Component: Dolomite or Dolomite Limestone with a chemical formula CaCO3·MgCO3. Source - Dolomite SDS from the company.

Calcium oxide (CaO) and Calcium Hydroxide (Ca(OH)2) both have a PH around 12.5. Sodium hydroxide (Lye) has a PH between 12.5 and 14. All three are very good dissolving a body quickly. I don't mess around with any of these for good reason, no one really should.

@outpaientzero Looking into this further, it is even more confusing because calcium carbonate has a pH over 9 and calcium oxide has a pH in solution over 11. So how exactly does an agricultural dolomite lime - such as Espoma - manage to get a product that is mix of calcium carbonate and calcium oxide (among others) to settle at a pH that is nearly neutral?

I'm going to fall back on a simple point in just the wikipedia page on calcium carbonate (under solubility): it is poorly soluble in water, and the extent to which it's soluble changes with pH and other factors like CO2 concentration. And if it's poorly soluble, the pH figures don't mean the same thing. Beyond that the chemistry is to me completely impenetrable.

I don't know exactly how the pH figures Kevin gives above are determined but I think the overall conclusion is that it's not directly relevant to using in a container mix - if it's not in solution, it's not the same thing.