Perlite ore is a naturally occurring substance in the Earth’s crust, superheated in furnaces like popcorn and expanded like popcorn to create the white bits put to use in your garden. Perlite is made of small, pebble sized bits of perlite ore and has several applications in the garden. …Mixed into soils, perlite is an effective tool to increase aeration, decrease water holding capacity, and lighten otherwise heavy soil compositions. Perlite can also be used to deter fungus gnats, by creating a 1-2 perlite layer on top of soil, fungus gnats cannot find a suitable soil surface to penetrate and lay their eggs. A favorite application of perlite is with coco coir, and growers utilize anywhere from a 30/70 to 50/50 perlite/coco blend. HTG Supply has on hand a large selection of perlite for every growing application, shop now to put the right perlite in your soil.