Mushroom Merchant Gypsum is finely powdered calcium sulfate dihydrate for edible mushroom substrate and grain preparation. It provides calcium and sulfur and mixes easily into your chosen recipe. Available in 1 lb and 5 lb bags for small batches or larger production runs.
Price range: $12.99 through $19.99
Mushroom Merchant Gypsum is 97% pure calcium sulfate dihydrate, finely powdered for easy mixing into mushroom substrate and grain preparation recipes. It supplies calcium and sulfur and is available in 1 lb and 5 lb bags for home growers and larger production batches.
Gypsum is a mineral supplement used in certain mushroom-growing formulas. Depending on the recipe, it can:
Gypsum does not replace the main substrate ingredients, proper hydration, or the preparation required for your growing method. Not every recipe needs it, so follow a formula suited to your edible mushroom species.
Measure the amount specified in your substrate or grain preparation recipe and mix thoroughly for even distribution. The appropriate amount depends on the ingredients and batch size.
See our Gypsum Dosage Instructions for guidance on measuring and adding gypsum. For substrate recipes that call for a 5% gypsum addition, use approximately 50 g per 1,000 g of dry substrate ingredients, measured before adding water. Mix thoroughly for even distribution. Follow separate dosage instructions for grain preparation.
Avoid creating dust or breathing in the powder during handling.
Our CVG Mushroom Substrate contains coco coir, vermiculite, and gypsum and arrives hydrated and sterilized. No additional gypsum is needed for normal use.
Keep the bag closed and store in a dry location to protect the powder from moisture.
| Weight | 1.2 lbs |
|---|---|
| Dimensions | 10 × 7 × 2.5 in |
| Size | 1 Pound, 5 pound |
| Chemical Name | Calcium sulfate dihydrate |
| Chemical Formula | CaSO4 · 2H2O |
| CAS Number | 10101-41-4 |
Jeff –
Good gypsum, I only used one other kind and this one seemed better
Debra –
This is good stuff and looks really clean.
Gary –
Decent so far
Jackson –
bought this and your agar premix on amazon. best quality gypsum i have found. I like that it comes in a small bag too because you really do not need much. my mushrooms are loving it!
Dave –
Hands down best gypsum for the price especially.
Rachy –
I bought this for my plants this spring, and they love it..I had high levels of salt and this helped a lot
M.w.F –
Growing mushrooms has been a hobby of mine for a little over a year now. Out of all the brands of gypsum (or any mushroom product really) this one seems to really value clean. The gypsum arrived in perfect condition, has instructions, and is noticeably better quality just by looking at it. I will continue to buy this brand, I am super satisfied.
Landon –
5 pound super clean and will last me a while!
Oscar –
The gypsum looks pure and has that fluff to it. For mycology, this is the best gypsum I have used. Will buy again.
Theo P. –
I am super satisfied arrived fast good quality gypsum and will buy again
victoria –
used it in my garden and my plants seem to like it
Piotr –
This gypsum is really high quality. Using it for my bulk substrate, a little goes a long way. Peace!
Stella –
Mixed feelings honestly. I purchased this for soil conditioning, but it looks like this type is mainly for growing mushrooms? Was not aware mushrooms needed gypsum! Company was helpful though and assured me it can be used for soil conditioning as well. Apparently it is the same, even BETTER they say! We will see. Good customer service though.
Antonio. V. –
Super Good!
gypsum soil conditioner –
bought on amazon for soil conditioner and it works great, my plants love it
Kev. –
great quality gypsum 5 star
James –
Works well.
Melly –
Got here in 2 days cant beat that!
Eddy –
I have purchased this 2 times now and will be purchasing again. Good gypsum for the price, and it has come quick both times. The only other way I have bought gypsum is the big 50 pound bags, and the ones I bought here is way more convenient and seemingly better quality. Over all I am satisfied.
Rodney Miller –
Only gypsum I use. Reliable, clean, and has arrived in perfect condition everytime.
Jen P –
fine powder easy to use
Jamie –
Flows nice, dissolved nice
LEO –
Best gypsum at the best price!!
MIKE –
I originally bought this to grow mushrooms, and it worked great for that. I had a ton of left over, and added it to clay soil in my backyard, which I am planting vegetables in this spring. Great stuff all around and I recommend this gypsum for any reason.
sam –
Good value, bought incredibly too much but will save for future grows lol.
NY FUN GUY –
Perfect if you don’t want to buy a giant 50 lb bag if you can even find them. This ends up being a fair deal and a great quality product.