Hydrofarm Plant!t Coco Coir Mix - 2.5 cu. ft. Block - retains water, making sure plants never go thirsty, but also offers excellent drainage and aeration. This unique consistency helps maintain the essential air-to-water ratio that enables plants to grow to their maximum potential. Growers can implement this pathogen-free media on its own, add it to potting soil for improved performance, or use in place of bark as an attractive and all-natural ground cover.