hydrated lime vs calcium carbonate

[chill]

Hi,

Can calcium carbonate be substituted one for one with hydrated lime or does it require a different recipe?

Oh, can anyone tell me where to get pickling lime? No one on in my city has heard of it. I checked feedstores, wally world, craft stores, canadian tire (hardware store), garden shops, you name it.

[bluehelix]

Hydrated lime should not be used. Calcium carbonate should be used to balance out peat moss. The only people using hydrated lime are hobbyists, and depending on the grade and exactly how much one uses, it could be a total disaster. Some grades of hydrated lime are extremely caustic and strong.

No mushroom farm in existence would use hydrated lime. In fact I challenge anyone to find me a single mycological text referring to it for casing pH balancing. There are numerous reasons why to not use it for this purpose. First, it has a pH of about 12.5 which means it can very easily create way too basic of a casing, burning the mycelium and killing it. With peat varying so much in its pH, there is no sensible way to use calcium hydroxide (hydrated lime) because one doesn’t know how much to add unless one has a very good pH probe, which cost about $100 to $150. Secondly, hydrated lime converts to calcium carbonate, a weaker base, upon a reaction with the air. This can take days or weeks depending on the amount of exposure and how much water is present. In the case of a casing, it would likely be about a week. After all the hydrated lime converts to calcium carbonate, the pH will fall. In the later flushes, the pH would continue to fall unless calcium carbonate chips of some sort were used. Calcium carbonate doesn’t lose its buffering ability so easily like that.

If one intends to use hydrated lime, it must be used (a) with a sensitive pH probe to monitor the casing since peat varies in pH a lot and the mix can easily become too basic, and (b) with the aid of some chip or powder form of calcium carbonate which can hold the pH up in the long run. I don't use hydrated lime at all. It's not used by the pros, and I see no benefit over using regular calcium carbonate which is the gentle buffer that is normally used.

Calcium carbonate powder can be purchased in the many forms. You can find it in a reasonably pure form at some garden stores sold as “garden lime” in the form of ground oyster shells, but read the label: you are looking for ground oyster shells, limestone, or any other form of calcium-carbonate-based lime, not dolomite-base lime (which is a magnesium-rich form). Another place to find pure calcium carbonate is from wine making shops. Call some home brewer shops and ask for calcium carbonate powder; they’ll know what you want. Another method to derive it from hydrated lime is to spread your hydrated lime no more than about ½ inch thick on the bottom of 13"x8" glass pan (do NOT use a metal pan), and cook at 350F for about an hour. The heat and CO2 in the air will covert most if not all of the hydrated lime to calcium carbonate.

[bluehelix]

chill, calcium carbonate and hydrated lime are totally different beasts. You certainly cannot use one for the other. It takes about 1.2 cups of garden-lime grade of calcium carbonate to balance out 15 cups of loosely-packed peat moss to a pH of around 7.5. If you end up using the very pure form of calcium carbonate used in wine making, use only 1 cup per 15 cups of peat moss since it's more reactive in my experience.

Calcium hydroxide (hydrated lime) varies in quality so much that one cannot really give very good recommendations of how much to use. The reason is because some forms have a lot more calcium carbonate in them than others. It's strength really depends on how the powder was protected from moisture and fresh air during storage.

[chill]

Hi Bluehelix,

thanks for that. Very helpful.

I did a little research and sources of calcium carbonate include tums and rolaids.

Good source, bad source? There is a wine store near me. I'll give them a call.

Your ratio of 1:15 for peat moss wouldn't apply directly to cactus mix which is only partially peat moss, the rest being made up of sand etc. I'm thinking that I'd use say 1/2 as much CC. Correct?

So:

Say I want two cups of cactus mix for the casing (500 ml) I would want 17 ml of calcium carbonate and 10ml of gypsum?

Originally Posted by bluehelix

Hydrated lime should not be used. Calcium carbonate should be used to balance out peat moss. The only people using hydrated lime are hobbyists,

I strongly disagree. I've been using hydrated lime exclusively for several years with zero problems. It's what stamets recommends at the masters seminar and also what the two largest commercial mushroom farms in my area, that I do lab work for both, use for production of edibles and medicinals.

The very rapid swings in ph that can be achieved with hydrated lime make it excellent for use in pasteurization of straw and other bulk substrates. I can pasteurize straw in hot water with a ph of 12, which neutralizes contaminants in their tracks. Once it has drained and sat overnight, the ph naturally falls to the perfect spawning level of 8 to 8.5.

In casing mixes, hydrated lime gives an immediate ph correction, and it lasts as long as the average casing lasts. I use one teaspoon of hydrated lime per cup of peat in my 50/50 casing mixes, along with a tablespoon of gypsum per cup of peat. The gypsum, which contains both calcium and sulphur, helps to moderate the hydrated lime. I have never, and I repeat never had problems with using hydrated lime. It is what I recommend over calcium carbonate due to it's very fast acting properties. If one can't find hydrated lime, then use pickling lime/calcium carbonate. But, in my opinion, it's a second choice, not the first.
RR

[chill]

Well I just called my local beer brewing store and they are willing to sell me BOTH calcium carbonate and gypsum.

This seems like a good tip for people in my situation (ie: not wanting to use 50 lbs of hydrated lime) who are having trouble finding supplies.

[waylitjim]

Originally Posted by bluehelix

Hydrated lime should not be used. Calcium carbonate should be used to balance out peat moss. The only people using hydrated lime are hobbyists. If one intends to use hydrated lime, it must be used with a sensitive pH probe to monitor the casing since peat varies in pH a lot.

I've used hydrated lime for almost every grow I've ever done, and with much success. I use it in my casing mixtures and for bulk substrate soaks. I've never had negative results from using it and I don't use a pH probe. I'm not dumping the lime directly on the casings, it always gets diluted during the pasteurization process. And yes, I am a hobbyist.

[anticheffy]

yea me too
hydrated lime is almost solely recomended in everything Ive read
I use it exclusivly and have NO failures

Im a hobbyist to though

[bluehelix]

Cactus mix is already pH-balanced with calcium carbonate to around 7.0. You don't need to add any more.

I am glad that some have luck with hydrated lime. The form I tried was very pure and so strong that it totally wiped out my entire bed almost overnight. The strong stuff is snow white and burns your nose. The weak stuff at garden stores is a mix of that and regular calcium carbonate.

Just because you found some super weak agricultural grade doesn't mean that is what everyone will find. Pickling lime, one of the most typical forms of hydrated lime, for example will not work well. I don't care how many grows you did with your weak garden lime, the fact is that others may find much stronger lime that hasn't reacted with the air for so long. Calcium carbonate, on the other hand, is much more consistent. You only have to deal with particle size, not how reacted it is with the air because it's stable.

As for using tums or rolaids, that too is a bad idea. Those are usually packed with all sorts of other things, sometimes including sugar and magnesium. Get normal garden lime derived from calcium carbonate sources or a pure form used in wine making.

[bassplar99]

Getting a lot of different info here. I have to ask, if you do not use gardening, agricultural, or gardening lime, what else is there? What brands does everyone use? And Rodger, I am curious since I follow your straw teks but would like to start using a steamer, how would you suggest incorporating lime into the pastuerization process? I was thinking a soak in warm water with lime for a period and them steam and hang to dry to the proper moisture. I would like feedback from anyone though, very interested in this.

[bluehelix]

Oh, and by the way, you can't really add too much calcium carbonate because it stops reacting much after you get a pH of around 8.0 to 8.4. Hydrated lime, on the other hand, stops reacting around 12.5, strong enough to eat the tissues out of your nose so don't breath the dust unless you want a really clean nose.

[bluehelix]

waylitjim, the process you describe, soaking and then pasteurizing, probably converts the vast majority of the hydrated lime to calcium carbonate. Heat and exposure to carbon dioxide quickly convert all the lime to calcium carbonate given a weak solution to begin with. There is a technique to pasteurize straw using calcium hydroxide where one makes a warm to hot bath of saturated calcium hydroxide (1 teaspoon per gallon is all that is needed for saturation), soaks the straw for a bit, and then lays it out to drain and dry. This technique is covered in detail in "Growing Gourmet and Medicinal Mushrooms" among others.

[bluehelix]

bassplar99, the strongest grade of lime I know of is food-grade (CODEX) hydrated lime. This is an extremely pure grade with and ultra find particle size (like flour) that is used for cooking. It's stored in water/air resistant bags. For example, it is used in the making of tortillas to boost pH to prevent premature molding. If you use that grade, you'll need to be very careful. Anything even remotely close to 1.2 cups per 15 cups of peat is way, way too much. It'd be closer to a teaspoon per 15 cups of peat, but don't quote me on the numbers. A soak in a saturated solution probably would work (as Waylitjim said), but if you are using cactus mix, you don't need to pH balance it because they've already done that for you! Just throw in some oyster chips or aragonite sand and you're good to go for a perfect mix.

[waylitjim]

Originally Posted by bluehelix

The form I tried was very pure and so strong that it totally wiped out my entire bed almost overnight. Just because you found some super weak agricultural grade doesn't mean that is what everyone will find.

Alot of respectable growers around here have used hydrated lime with much success. Just because you had bad luck with hydrated lime, doesn't mean everyone else will. Although most people have great success from using horticultural hydrated lime, some do not. Blue, I respect you as a grower, and I know you're a good person too. But I don't want people to get the wrong idea about hydrated lime. It works well, and professionals use it too as RR mentioned above, it's what stamets recommends .

Originally Posted by bluehelix

Pickling lime, one of the most typical forms of hydrated lime, for example will not work well.

Pickling lime is food grade calcium hydroxide (hydrated lime) with no additives or preservatives. Be careful with what you say, what works for some will not work for others and vice versa.

I'm not saying Calcium carbonate doesn't work well. But many brands of picking lime and hydrated lime work equally well. You can disagree, but it's been proven by various people here. The reaction of hydrated lime with CO2 gas = calcium carbonate, there's very little difference between the two. You do have to be careful with the kind of lime used, you never want to use dolomitic hydrated lime, always use high calcium horticultural hydrated lime with Mg. levels below 5%

Chill...sorry to derail your thread.

[bassplar99]

I shoudl clairfy also, I am only steam pastuerizing straw, not casing materials. Sorry got a little off topic but the discusion of lime was going on. I remember pickling lime for $2.99 being posted on here at one point as a good source of lime.

[bluehelix]

In casing mixes, hydrated lime gives an immediate ph correction, and it lasts as long as the average casing lasts. I use one teaspoon of hydrated lime per cup of peat in my 50/50 casing mixes, along with a tablespoon of gypsum per cup of peat. The gypsum, which contains both calcium and sulphur, helps to moderate the hydrated lime. I have never, and I repeat never had problems with using hydrated lime. It is what I recommend over calcium carbonate due to it's very fast acting properties. If one can't find hydrated lime, then use pickling lime/calcium carbonate. But, in my opinion, it's a second choice, not the first.

Ok, we must be talking about totally different types of hydrated lime here. What EXACTLY are you and Stamets using? If it's so advanced, why is it not mentioned in his texts? One teaspoon of what I have per cup would drive the pH to 10+ for days if not weeks, surely killing everything eventually. You say hydrated lime? I have 98.5% pure calcium hydroxide (aka hydrated lime). It's called CODEX Hydrated Lime and is manufacturered by the Mississippi Lime Company. Here is a specifications sheet:

http://www.mississippilime.com/produ...4&tabsetting=2

Now, I know exactly what I was using, and I know for a fact that you cannot use a teaspoon per cup. Now what where you and Stamets using? Do you want me to do an experiment to tell you how many weeks the casing pH remains above 9.0 using a teaspoon per cup of the hydrated lime I have? I am willing to do it. My guess would be at least a month before enough was converted to calcium carbonate to bring the pH back down to 9.0.

I am not saying it can't be used. I HAVE used it, but I was really careful with it. I also found the pH holding ability to totally suck compared to calcium carbonate. If you are shooting for one or two flushes, though, it probably doesn't matter.

PS - Oh and pickeling lime is hydrated lime. It's very close to pure hydrated lime too (over 98%).

[bluehelix]

Ok. I am doing the experiment now. I'll let you guys know how it turns out. I am adding one teaspoon of calcium hydroxide (hydrated lime) per a cup of sphagnum peat moss. I'll let you know how it goes.

Ok. I just did mix it up really well. The initial pH of the 1 teaspoon hydrated lime to 1 cup peat is 12.4 using a recently calibrated pH probe that is accurate to +/- .1

I will post each day updating you here. It's exposed to the air too so the pH should fall slowly.

[waylitjim]

That doesn't look like the type of hydrated lime recommended for growing mushies. You want Horticultural Hydrated Lime, not dolomitic or other kinds, otherwise like you say, it'll burn the mycelium and mushrooms wont grow. Hi Yield brand is a good one.

[bluehelix]

Here is the data sheet for it:

http://www.gardnwise.com/documents/msds/pdf/33362.pdf#search='Horticultural%20Hydrated%20Lime% 20Hi%20Yield'

Looks like pure calcium hydroxide to me. I wish I could get my hands on it. If anyone knows where to buy it, let me know. I'd like to examine this stuff for myself.

[spyker]

I dont know what grade of hydrated lime my FOAF has, but its like flour and the smallest bit sends the ph to like 12. He's ruined casings before but now is having excellent results with now that he's figured it out, soaks the horse poo in water for 2-3 days to allow germination of molds (the horse poo has lots of green,like the house ,no matter haha.). then rinses, soaks in the lime at 11+ ph for 2 days, then rinses, ph settles on about 8.2 after rinsing and pateurisation. works like a charm. Mycelium love it.

[waylitjim]

Hi-Yield Minimum Guaranteed Analysis
Calcium - 51%
Calcium Oxide - 72.50%
Magnesium Oxide - .45%
Calcium Carbonate Equivalent - 131%
Calcium Hydroxide - 95.79%

http://v-p-g.com/Labels/HiYield/Fert...me%20Label.pdf

[lost_onabbey_rd]

copyed ya'lls post to it's own thread
i'd really like to hear what anybody else has to say about this
RR says that he uses hydrated lime
as do 2 of the commercial companys he does some lab stuff for
bluehelix says calcium carbonate is the way to go
and from his recipies seems to be workmans choice
so lets hear it
what do you guys use
why, how much, and what have been your experiences
please post pics of the bags/brands if you can
LOST

Why, well because its the only brand I can get locally and it works well.

How much, for past. bulk substrates I use it in the water, never mixed with substrate. I use tablespoon for every 3 gallons of water.
For casings, I use a teaspoon for every 2.5 cups casing volume.
I also use teaspoon gypsum in casing.



I use the lime because it works for my substrates and casings. I check my ph also, though only once, before spawning, or casing.


*also, my brand has 20% magnesium. I know its advised this is detrimental and not wanted in the lime source. I have found it isn't a problem for me. *

[golly]

Last year i was perusing some agri sites for lime info...They clearly stated that unless Ag lime or calcium carbonate is ground finer than 100 mesh ,that it will have no reaction in the soil for at least 6 weeks and that even the finest grind of all may take 3 weeks to begin reacting....
The only unknown [for me] is whether mycelium can play a roll in speeding the reaction...All Ag lime applications are reccommended in the fall ,so it will become active by the following gro season..
Me likes the Hydrated lime -except when it makes me choke on the dust...

[Hippie3]

interesting discussion.
some experiments would be nice
but it's hard to argue that hydrated lime won't work
when we see so many cases where it does.

I use hydrated lime.

[blackout]

I use hydrated lime with success, I cannot find normal lime in my area. Some people use a combination, small bit of hydrated gets the ph up to 8, then the normal lime buffers, cheaper that way.

[Gamera]

Maybe a bit off topic but does anyone add gypsum? My recollection is that Stament's formula calls for small amounts but I could never figure why it would be necessary or helpful.

[Hippie3]

gypsum is added to help reduce sticky grain starches from clumping

[Gamera]

Originally Posted by Hippie3

gypsum is added to help reduce sticky grain starches from clumping

Ah, that makes sense. I was under the impression it was being used to buffer ph. Thanks.

That too. It isn't used in casing mixes simply to avoid clumping, although it does improve texture. For use in casing mix and manure/compost, it adds calcium and sulphur, which are both necessary for proper fruitbody development. As a result of the calcium and sulphur, gypsum is also a buffer that prevents wild swings in ph, always attempting to return the mix to neutral.

Blue, I'm curious what kind of ph probe you use that can be calibrated to .1 ph? The only ones I know that are that accurate are the bulb type commonly used for hydroponics. Those are intended to be used in clean, clear liquids in my experience, and are not accurate in soil. The probe type ph testers that use two dissimilar metals are so inacurate as to be unusable. I've found as much as a difference of +/- ph3 just due to how much moisture is in the sample. I'm just curious what type of tester you're using. I use the paper strips that change color, and use them by squeezing out some of the water into a clean dish and testing that. Be sure to wear gloves so the sweat on your hand doesn't contaminate the reading. I've used up to a tablespoon of horticultural hydrated lime per cup of peat, and still had the ph settle out in the mid 8 range within 24 hours.
RR

[Lazlo]

I'm a hydrated lime user as well. Howard Johnson's hydrated lime in the lime green bag is fantastic IMO. This lime is a bit stronger than calcium carbonate, but not that much. It says that 1 ton of this product is equal to 1.25 tons of calcium carbonate. Not drastic IMO. Especially if you're taking into consideration the smaller amounts we use.

[Bobcat]

My friend uses the kind sold for marine aquarium use. Typically very pure. One brand was even labeled "USP". Called kalkwasser (german, I think) in that hobby. Uses it with both gypsum and oyster shells. Never had any probs that I know of....

[blackout]

Originally Posted by Rodger

The probe type ph testers that use two dissimilar metals are so inacurate as to be unusable. I've found as much as a difference of +/- ph3 just due to how much moisture is in the sample.

I just got one of these yesterday. I found my cow manure was 4.5-5ph. I tested it in storebought compost and it read 6.5 as per the packet. In water it is 7. As long as it shows 7 in water and 7 in the casings/substrate it is good enough for me. I hate the digital probes, esp. as they are just for water. I know agar uses a dial one rather than digital too, but it is an really good one.

I would have expected the moisture in the sample to give different readings though. Surely if you add more water the ph will go nearer 7 whether it was higher or lower to begin with?

I added a fair bit of hydrated lime to the manure and left it sit overnight it is now reading 7. Can sodium hydroxide (lye/caustic soda) be used to adjust ph in casings? I heard of somebody using sodium bicarbonate (baking soda) which buffers at about 8.3-8.4

I always used pickling lime, from walmart.. Worked for me just fine.. But I am positive sodium hydroxide or lye would burn anything... If you get it on your skin, it'll burn right thru, that stuff is very dangerous to mess with...

[arezap]

I'm going to give the hydrated lime a shot. I can't find the pickling lime around here. It'll be a few weeks though. Gonna try bulk OI's on elephant dung from mycoshack.com,supposed to be available next week, and straw.

[anticheffy]

the stuff I use all the time is this

Hi-Yield (brand)
horticultural hydrated lime

minimum guaranteed analysis
Calcium (CA)...................51%
Calcium Oxide (CaO).........72.5%
Mag Oxide (MgO).............0.45%
Cal Carb Equiv (CaCO3).....131.%
CalciumHydroxide (Ca(OH)2)...95.79%
E.N.P.............................130.35
E.N.V.............................130.35%

I dont get the percentages listed but this is what the bag says
I use about a cup in a big ass rubbermaid of compost and about 2 tablespoons in a simmering pot of wheat that makes about 10 qts

stuff works great

[tripinstein]

I've never really kept tabs on what my casing PH level is or anything but I use Mrs. Wages pickling lime whenever I use peat in my casing mixture. I also ad before sterilizing as well. I have noticed that it takes a little longer for the mycelia to colonize the casing layer when I do use it as opposed to not, but I get more flushes before contams get a hold of it by using it as opposed to when I don't. So for me it works in helping get maximum distance out of my casings. Just my 2 cents.

[Hippie3]

poll's pretty decisively in favor of hydrated lime
8:1 ratio ATM

[MrMaddHatter]

I'm with BlueHelix on this one. With calcium carbonate, you just about CAN'T screw up.
Since using it, I've retired the ol' PH meter as its not needed.

Hydated lime is just too basic for me. Too much room for error, especially if you don't have a good PH meter.

Not that hydrated lime won't work.....I used it for years with no problems.
Just decided to go back to the old-school ways.

[Hippie3]

just dump the peat and use coir instead
you can omit lime entirely