Sol Soils offers a variety of high-quality soils, soil components, and soil toppers designed for potted cacti, succulents, and houseplants. We select and hand-mix the best ingredients to produce fast draining soils that help protect against root rot, the number one killer of indoor plants. Calcined Clay has become a popular soil amendment for all categories of indoor plants. Its purpose is to meter moisture in the adjacent soil to keep it from getting soggy or bone dry. Fired at super-high temps it clocks in at 74% porosity, which drains & aerates much more effectively than sand. At Sol Soils, we are passionate about the beauty of plants and the natural world.