Where to find Gypsum in Canada

Can't find it anywhere, my local hydroponics stores just look at me with a blank stare.

I don't even need much, like less then 1kg really of gypsum (calcium sulfate dihydrate), not the kind you use for your walls (though maybe that would work?) but the horticultuarlly dissolvable and active kind.

guitarguy10 said:

Can't find it anywhere, my local hydroponics stores just look at me with a blank stare.

I don't even need much, like less then 1kg really of gypsum (calcium sulfate dihydrate), not the kind you use for your walls (though maybe that would work?) but the horticultuarlly dissolvable and active kind.

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Kelp4less.

guitarguy10 said:

Can't find it anywhere, my local hydroponics stores just look at me with a blank stare.

I don't even need much, like less then 1kg really of gypsum (calcium sulfate dihydrate), not the kind you use for your walls (though maybe that would work?) but the horticultuarlly dissolvable and active kind.

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Look for Granulated Gypsum Soil Conditioner at hardware garden center. May need to make special order. 25kg for $35 covers 250m2

Amazon? Try one of the brewing supply companies. It's used as a water conditioner for making beer.

Do you know if the calcium sulfate they use for food (I think it's for making cheese, I dunno) is the same stuff, or rather works the same? (like is it dihydrate):

I only need 10g/cuft and I only have a few cuft, just growing in a small 2'x4'x5' tent.

haha looks like you beat me to it, but your post wasnt there when i was typing. So you've used it in a grow with good solubility etc.?

Could probably just crush up a sheet of drywall. 8$ for a sheet.

Corso312 said:

Could probably just crush up a sheet of drywall. 8$ for a sheet.

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probably, but has anyone done it, with analytical data supporting it's solubility?

Corso312 said:

Could probably just crush up a sheet of drywall. 8$ for a sheet.

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I'm talking out of my ass, but I do know there are glues and binders in drywall that probably aren't beneficial.

guitarguy10 said:

haha looks like you beat me to it, but your post wasnt there when i was typing. So you've used it in a grow with good solubility etc.?

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I've never used it. I just did a quick search for suppliers in Canada. If it's used in beermaking then it's water soluble. But if you're intent is to mix it into soil then that probably isn't what you need.

What @solakani recommended is what you would want if using as a soil amendment. You can get that off of amazon if they don't have any at a local garden store rather than a hydroponics store.

guitarguy10 said:

probably, but has anyone done it, with analytical data supporting it's solubility?

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GUARANTEED MINIMUM ANALYSIS
Calcium Sulfate 70.0%
Calcium 18%
Sulfur 13.0%
Do not bother collecting analytical data to support use of drywall in a soil application. Use an agricultural grade gypsum instead.

Relic79 said:

I'm talking out of my ass, but I do know there are glues and binders in drywall that probably aren't beneficial.

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I dunno.. I read something a few years ago how drywall was rejuvinating dead land and soil.

guitarguy10 said:

probably, but has anyone done it, with analytical data supporting it's solubility?

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I know it makes great compost

Corso312 said:

I dunno.. I read something a few years ago how drywall was rejuvinating dead land and soil.

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Maye, I'd still be worried about concectrated amounts in accumulating in the small volume of medium being used. Again, don't know much, but given the choice, I'd pick food grade before industrial is all. No argument, just caution.

Yeah i'm struggling to find much on amazon.ca, theres stuff on amazon.com but shipping to canada of that kind of stuff if fucking insane, and also takes too long.

And yeah ... if I had acres and acres of land and was looking for a cheap source I might consider drywall, but for the 1-4 plants I grow in 5 gallon pots, I'd rather just get some agricultural grade, i only need like 10g/cuft.

Are you following a soil recipe specifically? Maybe someone on the board knows a substitute for what you are needing?

And would Food Grade and Agricultural Grade be the same? If so, did you try the Health food, Beer and Wine making stores in your area?
It was mentioned above, and sometimes those places have things you wouldn't expect.

Garden centres and nurseries might have it too. Or the local farmers co-op. Both of those usually have way better prices than the hydro stores.

Relic79 said:

Are you following a soil recipe specifically? Maybe someone on the board knows a substitute for what you are needing?

And would Food Grade and Agricultural Grade be the same? If so, did you try the Health food, Beer and Wine making stores in your area?
It was mentioned above, and sometimes those places have things you wouldn't expect.

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I'm hoping to use a peat mix in my next grow that I learned about from Dr. Bruce Bugbee in one of his videos. It is 50/50 Peat/Vermiculte + 40g/cuft Dolomitic Lime + 10g/cuft Gypsum.

I have Promix HP though so basically 75/20 Peat/Perlite + Dolomitic and Calcitic Lime but it doesn't have the source of sulfur that gypsum provides. It's probably not even needed *shrug*

Home Hardware, Crappytire, even some Walmart's have agricultural gypsum.

Agricultural grade gypsum has not been approved for organic grows. I get most of my inputs from Gaia Green 4-4-4 for an organic grow.

INGREDIENTS: alfalfa meal, bone meal, blood meal, glacial rock dust, mined potassium sulphate, fossilised carbon complex, rock phosphate, greensand, kelp meal, and gypsum.