Growstone was founded in New Mexico in 1993 by eco-preneurs who saw the catastrophic damage strip-mining for products like perlite and Hydroton do to the earth. Growstones are breakthrough, high-performance growing mediums that are made from 100% recycled glass and 100% American …made. They provide superior air and water retention for superior results. Growstone Hydroponic Substrate is the perfect growing media for herbs, vegetables, fruit, and flowering plants including tomatoes, orchids, strawberries and gerbera daisies. They can be used in hydroponic grow systems as simple as manually irrigated containers, or as advanced as automatically drip irrigated containers, Ebb-Flow systems, and NFT tables.