I remember a great article in Make Magazine that described growing Spirulina.
I believe it was this article by Dr. Aaron Wolf Baum:
http://www.algaelab.org/2011/05/09/algaelab-diy-spirulina-ar...
A recent post (11/20/2020) on that blog announces that Dr Baum has started GreenSpring Farms in Brentwood,CA and is selling fresh Spirulina.