Keven makes a good point that begs the question, "Why use Kalkwasser?"
There are times and ways that I use it, but I consider it not only troublesome, but dangerous to use Kalkwasser as top off water, unless all top-off is being done over the course of 3-6 hours during the night. It's dangerous because to add Kalkwasser during the day might raise pH too high during the day, a time when pH is already at an optimum level.
It can also be wasteful. The CaCO3 which crystallized on the surfaces was the very Alk and Ca which Kalkwasser was supposed to deliver to the living organisms.
Oh, and to give a preliminary answer to the OP question, what is done next depends on how strong of a Kalkwasser solution is to be delivered and at what rate.
Aloha,
Mark
Edited by Mark Peterson - March 31 2014 at 6:51pm