ok so i've been thinking about something for a larger scale setup or even just a small scale with very little or no fresh air exchange. what if a guy was to take something along the lines of coco fiber or rock wool cubes. sterilize them. place them in between the cakes or around the outter edges of bulk sub. then take some grass seed, flash steam sterilize it for a min or 2. then plant 20 or 30 grass seeds in each cube when you are ready or right before you are ready to start fruiting cakes?? the grass will grow inside right along side of the cakes absorbing the co2 and producing oxygen with it for the mushrooms to use again.?? i would think that the grass would take up very little foot print or maybe as few as 6 square inches per tube large tube? six 1"by1" cubes spaced out evenly around edges.