Calcium and magnesium are only healthy. There's pretty hard water in most of Sweden too. Ridiculous.
Salts, silly.
Do you understand what salts are? Neutralised/combined positive and negative elemental ions? I am not talking about carbon-bearing forms of those elements in compound, which we generally need in high quantities to survive. We call that food. If we could metabolise these types of salts, there would be no need to farm the planet or hunt for meat. We could just eat the soil. These salts of various ions are a hazard to health in the concentrations presented in many local water supplies.
Mine is one where they have difficulty keeping the concentrations below the national specification without the addition of several other harmful chemicals. In theory, the harmful chemicals (which are intended to create combined colloidal compounds from the near saturation level of salts and then are filtered or settle out to be dredged up and hauled away later) are actually being ingested, due to the high demand for water in most cities and the city's inability to keep up with the demand. People are drinking and cooking with water that has, not only a hazardous level of certain salts, but has had additional coagulating chemicals introduced, but too little time passes before the water is needed by the public. So the action expected of the coagulating chemicals has not occurred, yet. It will still occur, chemically, but it happens inside our bodies!
All you have to do to prove the presence of these chemicals in your tap water supply, is to make some ice and allow it to melt in a clear glass. If there are coagulating solid-like (often white-ish) speckles settling on the bottom, then your water has some bad shit in it. Don't drink it!
Read up, some. Go back and study biochemistry for a bit, then we'll talk.
