Simon Mason wrote
Tim+ wrote

Okay, if soft water is widely considered to be a significant cause of
heart
disease, what's the simplest way of hardening a supply of drinking water
in
a domestic situation where the supply is naturally very soft?

https://www.sanpellegrino.com/uk/en

Stupid waste of money. There isnt a shred of evidence that there
is any medical problem with naturally very soft water, most obviously
with water that is collected from the roof of your own house etc.