I live in southern California and the tap tends to be hard. I'm about to set up a high tech tank and am wondering if an "auto water change" that pours tap directly into the tank is safe for any fish. I want to at least attempt rams this time but will need regular large water changes and don't want to strain myself doing it. My LFS has beautiful rams which are healthy and they have relatively hard water too. So would adding tap directly to the tank kill rams? I don't think I need RO since my LFS is able to keep them with our tap, but is the entire concept of adding tap to your tank bad enough to kill rams? Or is there another easy water change system that would work other than the bucket system?
Thanks

Michael