67 replies to this topic

[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]

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 .

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.mississip...04&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...d Lime Hi Yield'

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/Lab... Lime Label.pdf

[eatyualive]

also, i get pans to grow invitro pretty easily without a casing as well. but casings always rock with pans. the best part is the time between the flushes when you can just break the stems and case right over it. gotta love pans!:space:

[bluehelix]

This is a cool discussion. I have learned that hydrated lime does work somehow if done right. I am not sure the details since my experimental casing soil is still pegged at 12.4 with one teaspoon per cup, but it must drop given enough time. I am guessing Waylitjim and spyker have the key using a hydrated lime solution rather than pure powder. I would love to measure the pH of a casing done this way sometime. My guess is that it must settle down after a few days into the 8's.

At some point, I will write up the casing preparation technique I use. It's a little bit different than any other I have read. I do a lot of rinsing of the mix in a plastic cement sand bag before I pressure cook because I believe that a good rinse emulates the natural leaching of rain. Such leaching removes potentially harmful salts (including residual sodium chloride from oyster shells) as well as reduces the amount of silt in the peat which would otherwise reduce gas exchange. After seeing many types of mycelium rip through my casings in ways that you just don't see online often, I am convinced of the technique.

For example, in the attached picture you can see Viet Pan Cyan ripping through 1/3rd inch of a casing. The picture was taken only 5 days after I laid the casing! That colonization completeness in such a short time is only possible with a casing that is perfectly prepared coupled with an aggressive strain like Viet (which totally rocks so far by the way).

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[bluehelix]

It wasn't the next day and I didn't heat it. I'm going to heat the experimental casing now to very hot like one would with a pasteurization. Tomorrow it should be in the mid 8s. I am guessing the heat helps the CO2 in the air react with the hydrated lime to calcium carbonate. If that is right, the pH swing would double as super pasteurization agent, almost sterilization. I'll let you know tomorrow.

[bluehelix]

Industrial and this Hi Yield brand that everyone is using have about the same percentage calcium hydroxide according to the label, both are over 95%. I am using a standard Ag/AgCI pH probe. These are accurate to around +/- 0.1 point, and I have recently calibrated the unit.

Let's see what happens. I the experiment has not completed yet. I am going to wait and see if the pH drops to the mid 8s by tomorrow. It might do it. I just don't know.

This whole issue opens up a strange debate because the calcium carbonate equivalent of agricultural hydrated lime is supposedly only 135%. If that is true, then your 1 teaspoon shouldn't be too much. I am just going by the pH numbers, though. If the pH reads over 9 tomorrow, then it's too high no matter what. We'll see.

[altered_states]

Hydrated lime (horticultural) only gave me a problem once, when I used it to dust an entire casing layer.
That casing didn't pin until I washed the lime off.
Hydrated lime always worked perfectly for balancing the pH of peat-based casings, and drastically increased my overall success in almost all aspects of growing mushrooms.
Now I just keep it away from the pins.

[bluehelix]

The pH of the 1 cup peat to 1 teaspoon of hydrated lime after raising the temperature to boiling and allowing the mix to cool did go down. It is now 12.2 rather than 12.4 but still high enough to totally burn mycelium. I want to see this super weak hydrated lime everyone is using. Where do I buy it? I want to test it.

[waylitjim]

I want to see this super weak hydrated lime everyone is using. Where do I buy it? I want to test it.

There's alot of different brands out there that'll work. To name a few, Hoffmans, Bonide, Hi-Yield, Kellogs, and various brands of Pickling Lime like Mrs. Wages. As far as hydrated lime, I switched from Hi-Yield to Kelloggs because it's easier for me to find and works great. B.H, PM me if you want to find Kellogg's locally. Also for those needing a good source for Calcium Carbonate, check out Petco or Petsmart for a product called T-Rex Calci Sand. This is an inexpensive natural source of calcium carbonate. You can get a 5 lb. bag for under $10

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