Plagron PerlitePlagron Perlite is a lightweight mineral substrate made from expanded volcanic rock. Thanks to the high temperature kiln firing process, the material is porous, extremely airy, and has a high oxygen retention capacity. When mixed with soil, coco coir, or any other substrate, it significantly improves soil structure, promotes drainage, and prevents waterlogging. All of this results in a much healthier root environment, where roots can breathe and