Help With KH

[Madreefer]

So it turned off the kalk reactor and shut off my ph monitor for the calcium reactor. The effluent is still going. Well nothing has changed in the alk. Should I shut off the effluent? I also checked my test kit with some freshly mixed IO and it tested at what it is supposed to be at so the test kit is not the problem. What next? Should I be concerned with a kh of 15? It has been like this for 2 years. The old saying "if it aeint broke don't fix it" So is it broke?