Is my gypsum wrong

[Bio boy]

Online says gypsum says 22%ca and 19%s

mine says 39%so3 and 27%caO


Is mine wrong it’s agricultural gypsum and what I’ve always used ? I find different numbers online and wonder if I have some crazy different products for tractors or somthing

 

[VerdantGreen]

it should be fine if it is agricultural gypsum.. possibly the difference is down to purity or water content.
I use it at 4g per litre of soil mix.
VG

 

[Bio boy]

it should be fine if it is agricultural gypsum.. possibly the difference is down to purity or water content.
I use it at 4g per litre of soil mix.
VG

how come the numbers are so different ? this I use has a lot more sulphur in a different form than ca numbers​

where as it looks like they all here use a lower sulphur ? and higher ca
so if I apply the normal 8 cups to my soil mix I theoretically have more sulphur than most by a whopping 20%?
Thanks vendrant for the reply
Web======================
Gypsum is calcium sulfate (CaSO4). Refined gypsum in the anhydrite form (no water) is 29.4 percent calcium (Ca) and 23.5 percent sulfur (S). Usually, gypsum has water associated in the molecular structure (CaSO4·2H2O) and is approximately 23.3 percent Ca and 18.5 percent S (plaster of paris). Gypsum fertilizer usually has other impurities so grades are approximately 22 percent Ca and 17 percent S.

Ag gyp​

Description​

Agricultural Gypsum (Calcium sulphate dihydrate) is a CE fertiliser-grade gypsum obtained from naturally occurring mineral. It is used in a variety of agricultural applications including as a carrier for horticultural dressings, as a mushroom composting ingredient, as a soil improver and in land reclamation after salt water flooding. Agricultural Gypsum (Calcium sulphate dihydrate) is also very good at breaking down heavy clay soils.
Agricultural Gypsum (Calcium sulphate dihydrate) is a natural soil conditioner that will enhance growth of plants and grasses. As it is water soluble it will simply wash away leaving the goodness in the soil. It is simple and safe to use, simply spread by hand or machine on plants, lawns, etc.

cao 27%
so3 39%