Some people will claim that distilled water is bad because it doesn't have minerals in it. But any minerals in water are in trace amounts and any creature that's eating normally ought to be getting enough minerals in their food. Plus, the Navy distills sea water for the sailors to drink and you don't hear about Navy men suffering any ill effects from that. So I believe it's safe. But maybe buy drinking water instead of distilled next time, just because it costs the same and you might as well.