Growstone Hydroponic Substrate (Partical Size: 1/2") is a new substrate engineered to meet the specific needs of the hydroponic community. It is a 97% recycled glass product, manufactured in the USA that can be used as an integral component in many hydroponic systems. Growstones™ are developed to provide the ideal ratio of water retention and aeration while at the same time being light-weight, disease free, and packaged in a 1.25 cubic foot recyclable paper bag. Growstone Soil Enhancement  (Partical Size: 1/4") is also made from recycled glass. This product is an effective and eco-friendly component for any potting soil (coir-based or peat-based) in a variety of climate zones and environments. To find a hydroponics retailer near you, go to http://www.hydrofarm.com/.