I live in south Minneapolis and my tap pH was 7.6 the last time I tested. I have pressurized co2 on my planted 20L see my signature for pictures and details.
I've never really worried about the pH change during water changes. My drop checker always reads about 6.8 (green) during the day and is about 7.6 (Blue) during the night.
I keep Platies, otto's, plecos, and RCS.
Hope this helps.