The problem I had in getting rid of mine is that I can't reach all the places that they were. They were all over the rock, in the overflow and the sump. Unless you get them all they will continue to spread. Fortunately, introducing several peppermint shrimp combined with the kalk treatment did the trick for me. And yes, kalk them every day until you haven't seen any for a while. The peps are pretty good at getting rid of those little tiny ones that are impossible to see and all the others that you can't reach. I kalk all the others so that they focus on those.