I water mostly with rain-water year around.
Now if I go out of town in Summer ( my Orchids are all outside then), I have our tap-water faucet set on a timer and the sprinkler goes on for say 20 minutes once a day. Our tap water is very hard, but an occasional watering outside with that is not a problem, the next faith-based downpour will wash everything clean.
Here in NJ I don't have to worry about water temperatures in the Summer, it is fine.
