The cms subbox comes packed with some of the finest horse compost based substrate available on the market. Metered moisture content gives your mycelium the water it needs to produce healthy fruit without increasing risk of contamination. Compost substrates outperform coco/verm substrates because they mimic the natural environment more effectively and provide the correct nutrients to the developing mycelium. Instead of merely being a structure to grow on, our substrate is providing necessary minerals that accelerate the production of new mycelial filaments.