<<Disclaimer: Verify this information before applying it to your situation.>>

Sorry for the delay in summarizing.  Three people wrote and said they use
Earthrise which is supposed to be pesticide and additive free.  I found this at
the Whole Foods Store.  Someone was nice enough to also send their web page
http://www.earthrise.com.  They also recommended Frontier
http://www.frontiercoop.com.  One is a distributor for Cell Tech Super
Blue-Green Algae.  Someone else wrote from Australia that they use Life Stream
Spirulina New Generatioin.  I'm thankful for finding good brands of spirulina
which I consider to be a great supplement for me.  I'm a vegetarian and have
become lactose intolerant, so now I'm vegan.

Susanne