Just run a proper good quality coolant additive with straight distilled water and it will be fine in So Cal non freezing areas.
I run
Justice Brothers Super Radiator Cooler. I put and extra bottle of
Justice Brothers Cooling System Protector for extra electrolysis and corrosion protection when running straight water.
My Chinese aluminum radiator, Edelbrock aluminum heads look fine after 3 years of use. My stray voltage was 76 millivolt (max is 300mV) on 6/10/11 and was so my electrolysis is well under control. When I took the intake off on 3/1/14 is was .83 mV. passages look fine, no rust
Turbo Magazine coolant additive test: http://www.superstreetonline.com/how-to/engine/0703-turp-cooling-system-additives/
