The last time I had to replace my iron , I baught it at Walmart, & it said to only use tap water. But My sister told me , don't use anything but distilled, so I did. Now I've had my iron for several years & it never spits or anything like that. So I'm sold on distilled water. I had always been admiring the Rowentas, but after all I've read here today, I'll be happy with what I've got. Oh by the way I used to have one of those bottles with the holy top too. LOL!