Expanded perlite in the production of agricultural products (hydroponics, growing media):
- provides good aeration and optimum moisture retention for plant growth (high porosity)
- regulates drainage rate
- has a reasonably stable pH
- is sterile (high temperatures used for expansion)
- can be recycled
In hydroponic cultivation (growing of plants in a non-soil, supporting media) either in green-houses or in grow-bags filled with expanded perlite, it allows delivery of controlled amounts of water and specific nutrients to the plants and retains more air than the other materials, optimizing root development.
Regarding expanded perlite in growing media, a typical soil mixture with perlite (20-40% by volume) will have a pH 5.9-6.7, moisture content 10-45% and apparent density 90-150 kg/m3 (0,09-0,15g/ml).