No special water is needed. Any coffee connoisseur would tell you to use good purified drinking water though. It's just like beer. You get out of it what you put into it. The better the ingredients, the better the finished product. If you want the best cup of coffee you can make yourself, use good purified water and freshly ground beans in this machine. Unless you want to spend in the $500 range, this thing will be your best bet!