Perlite is a lightweight, inert, volcanic mineral expanded by heating.
Key properties
White, porous, low bulk density
Sterile and chemically neutral
High water-holding capacity while improving aeration
Uses in agriculture and horticulture
Soil amendment to improve drainage and aeration
Component of potting mixes (often 5–15%)
Medium for hydroponics and seed germination
Reduces compaction in heavy soils