Dealing with acidic tap water?

I was cooking a batch of red kidney beans tonight and, as usual for my setup, they seemed to be taking an unreasonably long time, even after a long soak. I tried adding baking soda and noticed a significant amount of foam in the water when I did. It has occurred to me that baking soda should not be foaming in water if the water is pH neutral, which seems to indicate my tap water is acidic, which would explain my recurring issues with getting the texture of beans right. Two questions: Other than beans and legumes failing to soften, what are some other common ingredients that I should be neutralizing the water before cooking? Is there a long-term solution (something like an installable filter) that you would recommend to neutralize the water coming out of my kitchen sink so I don't have to futz with baking soda and ratio guessing? submitted by /u/frustrated-rocka