Growstone 650CCM150 Coco Mix, 1.5-Cubic Feet, Brown/A Made from the finest coco fiber blended with 100% recycled, 100% American made Growstones Also includes redwood fiber with added mycorrhizae Ideal for heavy feeding plants in recirculating hydroponic systems or run-to-waste container gardens Allows for more frequent feeding per day with no risk of root rot