I find it cheaper to just buy distilled water in bulk, 0.23 cents per gallon, than to use something like you are suggesting. For example, say you buy a 600W pure distiller unit, which can process roughly 4 gallons of tap water in 24 hours, it would cost you around $2.80 to $3.20 in electric to run the distiller for 24 hours, which is pretty much the same price for buying distilled water at your local store. Anyhow, like I said, for someone like myself, needing 500 gallons of distilled water every few days, buying in bulk is my only option, But if you only need 3 - 5 gallons a day something like that "zerowater" pitcher is a pretty good deal, because each filter costs roughly $12.00, and each filter can process around 38 gallons of tap water with a pH that is less than 300ppm. So do the math... you can make 38 gallons of distilled water for each $12.00 filter, which comes out to roughly 0.32 cents a gallon, which is less than half the price of running a distiller with its resulting water costing you 0.65 to 0.80 cents per gallon.
