Using table salt or pickling salt from the grocery store is not 
advisable because most brands have anti-caking agents that create a 
turbid solution.  You do not have to use AR grade sodium chloride, 
however.  Food grade material, free of anti-caking agents, would be 
fine.

Dick

-- 
Richard W. Dapson, Ph.D.
Anatech Ltd.
Battle Creek, MI
800-ANATECH (800-262-8324)
email@anatechltdusa.com
Web address:  anatechltdusa.com