As I originally posted, I would use rain water for salt intolerant plants...a few trees, mostly.
I don't need good rain water for other plants/trees - crappy Phoenix city water will suffice for that.
Besides, most of my place is desert landscaped...and hardscaped.
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PS I don't even use city water for coffee-making or drinking.
I buy filtered water in four 5 gal. containers.
Then fill two 2.5 gal. containers with spouts...cooled in my fridge.
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Thanks for the input.