http://www.harveywatersofteners.co..../does-softening-water-cause-any-changes-in-ph says
When water is softened by sodium exchange, the pH rises slightly by about 0.2 to 0.3 units. This is because sodium is a stronger alkali than calcium, magnesium or other multivalent ions present in the water and which are replaced by sodium.
This statement was surprising to me. Not a big deal, but I found it interesting. However I find even more statements that softening does not affect pH. I don't know what the reality is. If there is an effect, I wouldn't think that 6 pH, 7 pH and 8 pH would all go up by 0.2 to 0.3 units. When I get my new pH paper, I plan to see if I can detect an effect. That's a pretty small difference to detect.