Just a couple of points too low, and it will sink over time. (peat-based mixes always do) Keeping the ph between 6.3 and 6.8 is best.

There are ph up drops (general hydroponics has one) available to raise water ph. Do not use an aquarium ph adjuster. And of course there's lime for the soil. But like I said, you'd be better served getting the info from someone experienced in raising the soil ph.

If you can't find the info online, would mix 1 tablespoon lime in the 3 or 5 gallon pot of soil (without the plant) and test for the results. Adjust as necessary.