BeGrow Rockwool Slab 3 Inch (H) x 6 Inch (W) x 5.3 Inch (H) - Case of 16Begrow stone wool slab is the basis for the root system development under hydroponic conditions. Suitable for growing vegetables, flowers and other plants in high tech greenhouses. Raw material is the key factor of our slabs manufacturing effectiveness. Stone wool used in the substrate manufacturing process consists of randomly arranged fibers. It allows to obtain the optimal rigid structure and extend the duration of usage in greenhouses for several