I too have been looking at them online. Some are 3 stage, some are 5 stage, some are RO/DI some are DI some are just RO. It all gets very confusing. And the GPD is another issue. Why would I need 200 gallons per day unless I have a commercial operation. Why would I even need 35 gallons per day. I only have 4 tanks, total of 310 gallons. I buy about 10 gallons of distilled water a week...so what size unit do I need?
I am, however, tired of lugging the 10 gallons a week from the grocery store. How do you decide what to buy?