I go between water in the iron and a spray bottle. I have a black and decker digital advantage which I like better than the rowenta. I kind of remember those references recommending filtered water saying tap water around the world is different so no telling what a comparison of tap water from California, New York City (think Flint, Michigan) or any other place would show. Probably different set of minerals and I guess no iron could be configured to work consistently with any or all versions of tap water.