Perlite
Revision as of 21:09, 7 April 2006 by Roberts.382 (talk | contribs)
1. An inorganic substance sometimes used as a soil amendment.
Perlite is a volcanic gravel used in potting soil, it is white and porous. It can be purchased for about $3.00 at most hardware/garden stores.
Source:http://www.shroomery.org/ index.php/par/7919