Filtering tap water (Brussels)

hello!
In the few months I have been living in Brussels I have been drinking tap water. With time I have realized how much lime it has (calcaire I think they call it in french), so I was sure this could not be healthy at all. I saw they sell some jars for filtering the water, so I was decided to buy one. But, a friend of mine told me that when you filter the water you also filter some mineral and good things that are in the water. Therefore I am not longer sure whether is better to filter it or not. Some people do, so do not. Anyone has good knowledge about this, mainly with the tap water from Brussels?
Thank you very much