In general you don't need to PH water for living soil unless your water is extreme, one way or another. Highly alkaline water can begin to lock things out weeks or more likely, months, down the line. It's so specific to your conditions it's really hard to give accurate advice. Most soils have peat + a liming agent to counteract the acidity of the peat...but after so many months that liming agent will be gone and your soil ph will change-so it's worth keeping an eye on at least, long term. You "probably" don't need to PH your water-is the best answer you'll get. If you do PH it, I'd just take it down a little, like 7 or so, and I'd use citric acid to do it-citric acid is GOOD for plants, they seem to love the stuff. If I were you, I'd look up your city's latest water quality report and just see how much alkalinity and calcium (and magnesium if it's on there) because that's good info to have for a lot of reasons.