Gypsum makes a superb additive for your mushroom growing (mycology) substrate.

Minerals and trace elements like calcium and sulphur can be found in Gypsum and will help your mushrooms at all stages of their development.

Gypsum will help you to maintain healthy PH levels and will stop grains in your substrate from clumping together.

Powdered gypsum is used to increase the pH in mushroom growing substrates. It is also a yield enhancer as it supplies minerals and trace elements to the mycelium.

Gypsum should be mixed at a rate of 2-5% of the dry weight of the substrate.