Expanded perlite is a mineral product that has been subjected to an expansion process at 1200 °C. It is an inert, stable, neutral (pH 6.5 to 7), sterile, lightweight insulator.
Its agronomic qualities include: high capacity to absorbe and retain water and fertilizer. It facilitates aeration, acts as a soil sponge and drains well. It also stimulates the initial rooting and a vigorous plant growth.
Perlite can be used to mix with other substrates or in recirculating hydroponics and those with solution loss. Because of its drainage capacity, expanded perlite will tolerate excess irrigation.