This article is from the Water for coffee FAQ, by Jim Schulman with numerous contributions by others.
http://www.corrosion-doctors.org/NaturalWaters/Frames.htm
http://wilkes.edu/~eqc/corrosion.htm
http://www.notcatfish.com/chemistry/hardness.htm
http://members.optushome.com.au/chelmon/Rbowkeep.htm
http://fins.actwin.com/aquatic-plants/month.9807/msg00114.html
http://fins.actwin.com/aquatic-plants/month.9810/msg00034.html
For further sources, Google on -- alkalinity CaCO3 hardness -- this
filters out the thousands of bozo pages that turn up for the more
obvious searches like -- water hardness.
 
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