I just realized that I’ve been drinking tap water (usually first boiled) since the last 4 years. Since I’m living in germany where the tap water is of good quality, see here and here I don’t need to think about buying bottled water anymore. I came to boiled tap water after I replaced hot coffee with hot tea and then replaced hot tea with just boiled tap water to prevent teeth stain. I also just save without any efford time and money.