This is only a problem if you use the dosing pump to pull the kalk directly. If you put the dosing pump to pull from RO/DI water reservoir then force through the reactor, the issue goes away.
Good:
RO/DI -> dosing pump -> Nilsen reactor -> sump
Bad:
RO/DI -> Nilsen reactor -> dosing pump -> sump
Essentially the kalk clouds up the tubing, etc., so medical drip pumps will not see the drip.