Our Shelmerdine Perlite is a naturally occurring mineral from expanded volcanic rock and is great as a soil amendment. Perlite improves aeration and drainage in potting mixes, and retains a small amount of moisture. It helps prevent soil compaction and promotes strong root development. It is dusty, so please take care to avoid inhaling the dust. Our Perlite is pH neutral and comes in a 3L or 9L bag.