Bit confused here. There’s levels to water hardness and what I listed you’d know pretty much instantly. It doesn’t sneak up on you or anything. If it makes you feel better I grew up in a town on a ravine lol it was all rock. You may not be dealing with the same situation.
ETA also limestone wasn’t the mineral that was the issue there, was a different one
I drink it now…on town water lol. Growing up outside of town proper in my area it did not taste good and left you more thirsty than when you started drinking it. The water was hard enough taking a shower felt like washing down with iron wool and if you stayed in more than five minutes you came out peeling. I was actually amazed the first time I lived in a town center on town water and the water didn’t make my skin feel raw lol. I was floored when I lived in a beach town and not only was the water mild, something in the area made the water taste slightly sweet and enjoyable to drink instead of “somewhat metallic from old pipes, but inoffensive cause it’s thirst quenching instead of thirst exacerbating”.
I’m not a mineral person going to be honest (I work in healthcare lol), so not sure I can really answer your questions. Also sorry being a bit cagey didn’t want to dox myself before a google, like felt 99% sure this was a common mineral, but again not a mineral person.
Basically I lived in some foothills along a ravine made of granite. Home 1 I think we had a neighborhood well and home 2 was a personal well. I can’t list the equipment being used to soften the water (if at all), I just know neither were on town water and home 2 I helped my dad install a softener since there wasn’t one (which tbh didn’t help too much besides making the water coming out of the faucet less cloudy and mildly less thirst inducing).
I don’t think my hometown has a lot of limestone (idk may be wrong, like said I’m not a mineral person, all I know it’s a granite ravine) so can’t comment too much beyond that. This was just my experience with water growing up and what put me off it for a long time.