10 lbs 【WELL DRAINAGE & EASY MAINTIAN】The porosity of lava allows for better soil drainage while maintaining moisture to allow your succulents, cactus bonsai trees and other plants to cultivate and flourish. On the other hand, additive porous lava rocks will also help maintain necessary moisture in soil for plants growing and better breath 【CUSTOMIZABLE MIX】 Porous lava rock soil additive can be mixed with ingredients such as pine bark fines, granite grift, calcined clay and peat to create soil specific to your plants needs 【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 filling aquariums, ashtrays, fire media, garden soil amendment, fire pits Add 1/3 pot of lava rocks at the bottom if your soil is not good at draining. Dressing up your bonsai surface with crushed red lava.