Expanded perlite ore is an excellent aggregate to add to growing mixes, or even on it’s own in hydroponics environments. It is a volcanic mineral, that when it is heated (to about 871C) the particles pop in a similar fashion to popcorn and forms a very light, white material.
Similar to LECA, each particle is made of many tiny closed air cells. Tiny cavities cover the surface which creates a very large surface area in which moisture is held. Roots therefore have access to this water. At the same time, the shape of the individual particles creates air passages between the particles and hence provides aeration and prevents root rot. Because it is sterile and appropriate fertilizers should be added. Different grades or sizes are suitable for different applications.