Soilless growing media contains no nutritional value for the plants. Soilless mixes are made of volcanic rocks and other inert medium. While containing no microbiological life. Soilless growing mediums such as perlite, growstones, and moss all have different advantages when used for hydroponic growing. Perlite and growstones allow for a reusable medium that you can recycle into your next growth cycle. Moss can be used when you need to allow for a moist growing environment. Contact our knowledgable staff for help with figuring out your grow medium for your hydroponic growing system.