Gypsum (Mushroom grade) - 950g

Fine powdered mushroom-grade gypsum. This provides

Add small quantities to bulk substrates to improve the pH and to provide nutrients for the growing mushrooms to improve yield and rate of growth. It is also well-known to improve the physical properties of prepared substrates and mushroom composts - making them less sticky and better aerated.

Typically gypsum is added at a rate of 2-5% by DRY weight of substrate.