Save when you buy the 6-pack: six 5 lb bags, 30 lbs total. Our bulk mushroom substrate is pasteurized, hydrated to field capacity, and ready to use straight out of the bag. Mix it with your colonized grain spawn in a monotub, or fruit right in the bag. What's inside Coco coir, vermiculite and gypsum: a proven base that holds moisture and supports healthy mycelium growth. Azomite and worm castings: added minerals and nutrients for strong colonization and fruiting. Details Pasteurized and hydrated: no soaking, mixing or measuring water. Six 5 lb bags: 30 lbs of substrate total. Grows two ways: use in a monotub or grow bin, or mix and fruit right in the bag. Filter-patch bag: heat-sealed bag with a 0.5 micron filter patch for gas exchange. Made fresh: every bag is made fresh and shipped to your door. How to use Mix: combine the substrate with your colonized grain spawn (not included) and mix evenly. Most growers use 1 part grain to 1–3 parts substrate. For example, a 5 lb bag of substrate pairs with about 5 lbs, 2.5 lbs or 1.7 lbs of grain. Colonize: keep it covered in a warm, dark spot (70–75°F) for about 3 weeks, until fully colonized. Fruit: fruit in your monotub or directly in the bag. Using a grow bin? Clean and sanitize the bin first, then mix in the substrate and grain spawn as above. Note: This product contains no mushrooms, spores, or mushroom culture. It is a growing medium for home mushroom cultivation.