For the love of god, listen to what you already know. This guy is a nut-job who sells an over-priced water distilling machine to people hoping for a miracle. It's disgusting.
Please read this: http://www.chem1.com/CQ/johnellisbunk.html
I don't know anything about treating wells and cisterns and neither does John Ellis or anyone else who bought one of his machines.
Please seek advice from a professional with your hard-earned money.