thanks. I'll look into it. I think its possible to have high calcium and low alk.
I found a good article for solving calcium/alk problems.
http://www.advancedaquarist.com/issues/nov2002/chem.htm
Looks like I'm in Zone 4. After testing for Alk, if its less than 4 (most likely), I'll be adding Alk supplements to put me in Zone 1. Then let precipitation bring me back to the right levels.