【IDEAL DRAINAGE】 These lava rocks are all natural and organic. Ideal for pots with no drainage holes you can place the lava rocks at the bottom of the planter so the water can pool without drowning the roots. Lava rocks are porous and will absorb and slowly release excess water back to the plant. Perfect for preventing root rot. 【PACKED】The black lava rock is 5LBS.Well packed and simply tear off the top then reseal. You can take the portion you need with the cactus and succulent soil mix, and then seal it back for perfect prevention and storage. 【PROFESSIONAL FORMULATION】 This lava rock is made up professional formulation which keep its well drainage and also supply the necessary nutrition for plants growing. It is best for succulent hobbyist and other succulent lovers 【MULTI USAGE】Lava rocks not only can be used as a soil additive, or top dressing in the art of bonsai, or bottom layer, they but also can be used for ashtrays, garden soil amendment 【OTHERS】The sizes of the pieces are 8 - 14 mm approximately and these volcanic lava rock is perfect for diffusing aromatherapy essential oils!But you need to cleaning until there are no impurities. Lava Rocks for Plants -100% Pure Volcanic Rock No Dyes or Chemicals-Best Lava Stones Top Dressing for Cacti Succulents Plants,Bonsai