Our water practically has rocks in it. Rain water would be wonderful but, it doesn't rain enough to keep my plants in water. I have a small Reverse Osmosis filter and a tabletop water distiller, used only for the more sensitive orchids. The rest have to make do with hard as rocks water.
Andy from Andy's Orchids recommends Reverse Osmosis, de-ionization or distilled water. Guess it doesn't rain a lot in San Diego either.
