Not really. In a high demand system like the sps tank, I add a little carbonate to my make up water along with what the calcium reactor adds. My levels are 5.0 meq/L total alk, 400-450 mg/L, and ph is 8.3 rock solid.

There is some lime buildup on the sump, and the air inlet on the venturi for the skimmer has to be cleaned every few days. Other than that, no real problems. But, that's just my experience.