[Razorback1980]

Actually ph balanced water (distilled) is completely noncorrosive at any temperature which is why distilled water is recommended. It is the metal content within unpure water that makes corrosion. Corrosion occurs with two dissimilar metals have an electronic connection between them. The better the current path the more corrosion occurs. Salt water for example is more conductive to electricity than tap water, therefore more corrosion occurs in salt water than fresh water. That's the basis of cathodic protection. I used to work for the National Association of Corrosion Engineers based here in Houston and have read much more on the subject than I really cared to...but it is pretty interesting. Antifreeze reduces corrosion by increasing the resistance to electrical current. The negative side to reducing electrical current is that it takes away the heat transfer properties as well. So if you do use pure water, make sure it is distilled.