Perlite is a naturally occurring mineral that forms when obsidian is heated to extreme temperatures and then cooled very quickly. The rapid cooling forces out the moisture in the material and leaving a porous surface in the medium. This results in a very light weight substrate that has great aeration properties - making it a great choice for hydroponic and soil based growing.
Using perlite in hydroponics is extremely effective when growing plants that require a large amount of oxygen, and good drainage. Perlite is incredibly effective for rooting cuttings as the high aeration allows roots to develop without getting drowned and rotting. We have had success with perlite in the past growing indoor plants, herbs and leafy greens.
It should also be noted that perlite floats - so take this into consideration if you are designing your own system! Dutch bucket systems and drip irrigation systems work great with perlite!
Perlite can be mixed with vermiculite, peat moss, coco coir and regular soil to increase aeration and drainage characteristics. Plants that require dry conditions such as cacti, sago palm or snake plants will thrive as the drainage that perlite offers is ideal for their growth. It is a versatile medium - so you can experiement with the ratios of different growing mediums as you need to suit your plants needs.
The surface of the perlite has tiny holes all over that allow incredible root aeration, and increase the available surface area for nitrate crunching bacteria to grow, making it an effective bio-filter - perfect for aquaponic systems.