I have the Silvonic 1G from Elixa.com that makes a gallon at a time, has a 
magnetic stirrer, and a lifetime warranty. www.elixa.com/silver/Silvonic1G.htmI 
checked out all the other systems and these guys answered all my questions 
clearly and quickly. Excellent customer service and fast shipping.They also 
have an inexpensive nebulizer and an ointment kit.Cool instructional videos 
too. I follow their advice about usage... "when in doubt, use more!"Abe