Soilless media such as perlite and vermiculite do not provide nutrients to plants. Soilless media are almost neutral in pH level and will not interfere with nutrient solution.

Used alone or as a combination, these Soilless media are great for crops like lettuce because vermiculite retains moisture while perlite provides adequate oxygenation and will not disturb delicate root system. A 50/50% mix of both perlite and vermiculite is recommended for an ideal balance of water retention and aeration.


 

Additional information about perlite
Perlite is not a brand name but a generic term for a naturally occurring siliceous rock. Perlite is a natural glass that when heated, it expands from four to twenty times its original volume.

When quickly heated above 1600 degrees F (871 degree’s C), the crude rock expands in a manner similar to popcorn as combined water trapped in the perlite vaporizes and creates tiny bubbles that make perlite light-weight. Crude perlite rock may range from transparent light gray to glossy black, while the color of expanded perlite ranges from snowy white to grayish white.

Expanded perlite can weigh as little as 2 pounds per cubic foot (32 kg/m3) making it suitable for numerous applications such as horticultural and industrial. Perlite is a form of natural glass and it is chemically inert with a pH of approximately 7.