Resident in the Lake Constance region with my family I have the problem of extra-calcareous water. Specifically "had" I this problem. A Brita Classic equipped with the filters Pearl is the optimal "Kalkreduktionskombi". Kalkausbeute after decalcification of kettle and coffee was more than low and does not believe it or not: I dare again a glass of tap water to drink without a furry tongue feared to need. Previous reviews regarding "fishy smell" I can not confirm. Insert the filter, discard the first 2Durchlässe and enjoy :)