This is a complicated issue, the pH I mean. There are other reasons for a higher pH in the source water, and some of these can change as the water passes through the pipes, enters your tank, is exposed to air, reacts due to biological processes, etc, etc. My action given what we now know would be to test the GH and KH of the water myself, or take a sample to the store.
Your best course of action is to accept the water as it is, and see how the pH settles out over a few weeks. No problem using organic things like wood, dried leaves (a common substrate material in many habitats), etc, but not aimed at somehow adjusting the pH. It will react and settle on its own. That will be your environment and suited to the fish. Future fish should share these parameters to avoid issues.
