Fini,
You and I usually do not agree on ANYTHING, as you are usually wanting to waste money on some type of gadget that somehow is going to single handedly "Save the world from ourselves" in some type of so called "Conservation", and to this I must add another disagreement.
Unless you somehow live in a region of the world that is experiencing a water shortage, due to draught or sever contamination, I again feel that your just flushing MONEY down the drain. Before you WASTE your dollars, why don't you contact your local water supplier and ask for a copy of their Federally required testing data. Then do a little research on the amounts of minerals that your body requires on a daily basis. You might just find out that your local "unfiltered" municipal water supply is healthier for you than the RO water that you think is so great.
Unless you are trying to keep a Live Coral's in a Salt water tank, and/or have a Chlorine problem with your water supply there is no need for that drastic of a water purifier in nearly anywhere in the continential United States.
To top it all off, the only reason to have a RO unit for a saltwater coral aquarium is not because the water you have is bad, but rather, it's easier to add minerals in a certain leval (which coral's are VERY sensitive to) to pure water, rather than water with unmeasured levels of minerals in it.
Really, I'm not trying to Peeve you, I'd just like to see the Tree huggers of the world use a little common sense, and it seems that your easilly sucked into that Montra.