16 replies to this topic

[Boylobster]

I've seen gypsum referenced by some of the heavyweights here on Mycotopia, notably the venerable Rodger "Know it all" Rabbit, but I haven't been able to find much solid info about it. Furthermore, it doesn't seem to be in the glossary! Tragic! :eusa_thin Some quick questions, if anybody'd like to help...

1. What's it do?
2. Are all gypsum products created equal?
3. Where would you look for good gypsum?
4. How would it be utilized, generally? (i.e. casing, sub, prior to PC/Past or after, etc...)
5. In what quantity, relative to the medium?
6. And finally, is there anything important to know about using gypsum in conjunction with Calcium Carbonate as a slow Ph buffer?

That's about all I can think of for now. I've very new to the hobby, and would much appreciate the patience of anyone that could help a brutha' out. Thanks in advance, guys. Cheers!

[Leary's Ghost]

how bout could someone elaborate on the difference between calcium sulfate & calcium carbonate? i.e. gypsum vs the primary ingredient in ag. lime.

both obviously contain calcium and i have seen both mentioned for use in our hobby. are they interchangable or do they have different specific uses?

[TVCasualty]

6. And finally, is there anything important to know about using gypsum in conjunction with calcium carbonate as a slow pH buffer?

Gypsum is weakly acidic, but takes time to break down and has a negligible effect on substrate or casing pH for the relatively short duration of a grow, so gypsum and CaCO2 don't really cancel each other out, but you should use a very fine grade of whatever pH buffer you do use (lime or chalk) so it can be utilized as soon as the mycelium needs it. Gypsum also adds sulphur, another essential element for mushrooms. I use a gram per quart of WBS, or a pinch in BRF style jars.

It really does make shaking jars easier. I always use it.

[shobimono]

Drywall is made of gypsum, so is blackboard chalk (not the mineral chalk)

[Leary's Ghost]

Gypsum is weakly acidic, but takes time to break down and has a negligible effect on substrate or casing pH for the relatively short duration of a grow, so gypsum and CaCO2 don't really cancel each other out, but you should use a very fine grade of whatever pH buffer you do use (lime or chalk) so it can be utilized as soon as the mycelium needs it. Gypsum also adds sulphur, another essential element for mushrooms. I use a gram per quart of WBS, or a pinch in BRF style jars.

It really does make shaking jars easier. I always use it.

so would it be correct to say that:

both help to keep grain from clumping and provide calcium. CaCO2 is less acidic than gypsum but gypsum provides sulfer.?

[TVCasualty]

Almost.

Gypsum is acidic, lime is alkaline. You need lime or chalk to buffer the pH as the substrate ages. Gypsum provides some sulfur and it helps prevent clumping in jars. I guess they both provide some calcium. The acidity of gypsum is weak, so it has almost no effect on the pH when you mix it into the substrate.

[Boylobster]

All accolades and general prostrations in your direction, TV! You just splattered my brain with a well-placed information "money shot!" Gross. And much appreciated. You too, Cap; thanks for being so swift to answer the call.

From my browsing of Myco.net thus far, it seems to me that many people are unaware of the potential benfits of an additive such as gypsum... references to it seem (in my less than comprehensive experience, I admit) infrequent and indistinct as to application, quantity, etc. Do y'all think this is because it's not markedly beneficial (obviously plenty of teks work well enough without) or perhaps that some or most subs & casings already provide sufficient calcium/sulfur/texture?

Hmmmm... perhaps some qualitative empirical comparisons will be my first real contribution to the community.

The differences are always in the details and I wanna grow like a pro, or at least like the people that post pictures of prodigious numbers of massive mushrooms. Up, up, and away!

[TVCasualty]

You just splattered my brain with a well-placed information "money shot!" Gross.

Interesting metaphor for learning something new. I think I'll only give further advice to hot but dimwitted sorority pledges. The towel I provide represents "taking notes." Basically, it's like you said: Gross. :neutral:

[Leary's Ghost]

Interesting metaphor for learning something new. I think I'll only give further advice to hot but dimwitted sorority pledges. The towel I provide represents "taking notes." Basically, it's like you said: Gross. :neutral:

hehehe
i like the way you guys can
turn anything into sexual inuendo
i love this place

[Leary's Ghost]

Almost.

Gypsum is acidic, lime is alkaline. You need lime or chalk to buffer the pH as the substrate ages. Gypsum provides some sulfur and it helps prevent clumping in jars. I guess they both provide some calcium. The acidity of gypsum is weak, so it has almost no effect on the pH when you mix it into the substrate.

OK, would it be more acurate to say:

• gypsum is primarily used to prevent grain clumping
• CaCO2 is primarily used as a PH buffer
• therefore, gypsum is typically added to grain jars/bags while CaCO2 is typically added to substrate.

[TVCasualty]

OK, would it be more acurate to say:
gypsum is primarily used to prevent grain clumping
CaCO2 is primarily used as a pH buffer
therefore, gypsum is typically added to grain jars/bags while CaCO2 is typically added to substrate.

I believe so, yes.

i like the way you guys can
turn anything into sexual inuendo
i love this place

I think we have ubiquitous internet porn to thank for that. There were some things I never wanted to get desensitized to (or even hear about), but I guess it's too late for that now...:eusa_thin

[Bobcat]

Gypsum is most beneficial in many areas of mushroom growing but arguably most beneficial in the composting process. This is because the microbes benefit from the calcium and sulfur and because of the anti-clumping nature. But thats a benefit you'll see only if you compost. Since most here do not compost, most here don't have that use of gypsum.

Most grains are also already high in these nutrients, so if you spawn heavy (again, as most do here- if they even do bulk) you are getting plenty.

Gypsum, imo, is a lot like nitrogen. I believe it helps. But how is it generally recommended to be applied? By adding grains and brans- which coincidentally add carbs and nutrients. So should we add blood meal or just spawn heavy with grains? Or just grow with cakes? The answer to me is fairly clear.

Commercial cultivators spawn low, because most buy their spawn. People here either don't spawn (grow from cakes or grain) or they spawn heavy (1:1,2,3,4 or 5- generally speaking). To put this into perspective, lets look at the numbers a different way. Commercials growers often try to achieve success at less than or equal to a 5% spawn to bulk ratio. People here try to achieve success at a 50% to 20% or more spawn to bulk ratio.

I'm not trying to ramble on here, just trying to point out that there are some reasons that people here are generally not pointed towards gypsum use.

[Boylobster]

I think we have ubiquitous internet porn to thank for that. There were some things I never wanted to get desensitized to (or even hear about), but I guess it's too late for that now...:eusa_thin

Ahhhh.... mourn with me our collective loss of innocence, the unwanted progeny of the new information paradigm and our own curiosity. On the other hand, some of the foulest shit ever to invade my mind I think I'd heard by the sixth grade. The internet now just gives me full-motion video to prove that those things exist. :neutral: Go figure.

[wayback]

Using a pinch of gypsum in a qt of rye grass has helped me reduce the from grain clumping. Of course, remembering to shake those jars after PC-ing also helps, but not as much.

I too had a hard time finding gypsum in a pure form, so I found that a pinch of Plaster of Paris, which contains both gypsum and lime, has worked for years.

[TVCasualty]

Bobcat: The whole time I was responding about gypsum I had the nagging feeling I was missing something... Compost! Of course! I am one of those people you mentioned who doesn't make their own compost (at least for fungi). It did seem to me that when I forgot to add gypsum to a grain jar it was more difficult to shake than jars with it included.

I guess gypsum is not a detail to spend too much time worrying about...

[Bobcat]

Well, if it works for you TV, then go with it. I've never added it to grains so I can't attest to how well it works on shaking. But I bet your right that there is an improvement.

But yeah, I agree that its not a big deal to worry about. But Im not trying to discourage any experiments.