I live in an area with moderate to very hard water, depending on the month.
I put in an under-sink RO system, Whirlpool branded, sold by Lowes. It's less than $200 and easy enough to put in yourself. If you have a water softener, feed it with the softened water because the membrane lasts longer and it will easily reject all the sodium ions the softener replaces the calcium with.
If your tap water is just very high in minerals, but nothing undesirable, you can just blend tap and RO water to arrive at the right mixture of minerals.
In the meantime, boiling your tap water, stirring it, then let it rest and cool down quietly will remove the scaling hardness and make it suitable for espresso.
Best bet, get a water test and figure it out.