Well, I'm extremely bored untill next week when work starts for the summer and I've been reading up on routine maintenance that's good to do. My Haynes manual recommends a cooling system drain and flush which as far as I can recall and my records show has never been done. Here's the question, in San Diego we have rock hard water, and by that I mean calcium in the water (we get the sloppy 23rds or whatever from the Colorado river. When I flush the system with hose water (Haynes recommendation, stop me if there's something better) will the calcium have any effect? My apologies if this is a trivial question, but I just want to make sure. This beast has to make it through grad school which is far off and I don't want a decaying engine block. As always, thank you for your time and knowledge.

Kienan