Stop the limewater (kalkwasser) addition until the alkalinity declines to a normal value (say, 11 dKH). Then restart it using less (that is, less solid lime in the same top off water).
Boost the calcium with calcium chloride as detailed in this article and using this calculator to gauge the dose:
Solving Calcium and Alkalinity Problems
http://www.advancedaquarist.com/issues/nov2002/chem.htm
Reef chemicals calculator
http://home.comcast.net/~jdieck1/chem_calc3.html