We sourced the finest coco fiber and blended it with our 100% recycled, 100% American made Growstone¨. What we created is a mix that can't be matched. GS-3 Coco-Mix combines the high porosity of Growstone¨ with the great water holding capacity and biological benefits of high quality buffered coco coir and redwood fiber, topped with a high concentration of mycorrhizae from Xtreme Gardening (RTI).