Viastone Expanded Clay Rocks, 10-Liter Increadibly resourceful growing material pH neutral If you like hydroton or lecastone you will love this product Please visit our Amazon storefront for a complete selection ViaStone, an incredibly resourceful growing material, is derived from clay. Clay itself is renewable and plentiful making ViaStone a premium growing medium due to its ecologically sustainable quality. Use ViaStone virtually anywhere: the greenhouse, in propagation systems, for outdoor gardening, around shrubs &amp; trees, as compost aeration, or as a hydroponic growing medium. &bull; pH neutral, porous, lightweight, and reusable &bull; Helps increase yield quality &amp; quantity&nbsp; &bu...