NORTH SPORE CVG (Coco Vermiculite Gypsum) Sterile Bulk Substrate, 5lb Amino Acids & Vitamins and guitar rooms where humidity and guitar rooms where humidity must be kept to a minimum and avoid foliar application under intense lighting or environmental conditions likely to cause rapid drying or leaf stress It is best practice to wait a minimum of 1 week after arrival before using sterile substrates to ensure they were not compromised during transit Our ready to use CVG blend starts with our own RHP certified MycoCoco as the base (the first coco coir researched and selected specifically for its mushroom cultivation qualities)