Harris Horticultural Grade Perlite is ideal for promoting root growth and healthy soil in container plants. pH Neutral, non flammable, and non toxic. Will not shrink or decay overtime. Helps soil to retain moisture and nutrients while preventing root compaction. 8qt size, chunky and coarse. Ideal for orchid, cactus, and succulent planting mixes that like to be on the drier side, and in hydroponic setups as a standalone growing medium. Aerates soil and prevents root compaction allowing your plants to thrive like never before. Commonly used in combination with coco coir bricks, soil and pellets.