Perlite is a soil-free growing medium that has helped to add aeration to soil mixes for years. It's created by air-puffing volcanic glass to create an extremely light and porous material. It has one of the best oxygen retention levels of all growing media because of how porous it is.
Its weight can be a downside in certain hydroponic systems where water interacts directly with the growing media, causing it to shift around and wash away. Because of this, perlite is rarely ever used alone – typically it is mixed with coco coir, soil, or vermiculite.
Benefits of Perlite:
Lightweight
High oxygen retention level
