I test my saliva PH first thing in the morning before I brush my teeth. You can buy it at health food stores, even tropical fish stores. Distilled water is definately 5-6.5PH. Reverse osmosis is really low as well. We are meant to drink flowing water, which is usually 7-7.2PH. Tap water that has fluoride added is horrible. That's why people started to drink bottled water. But the ph drops while it sits in the bottle, or the water ph was already low. Unfortunately, you probably don't have access to mountain water. Maybe you can research water PH in your area. If there is one, it's probably a small company.
What I've learned about fluoride is the stuff that flows in streams is calcium fluoride. Fluoride ions are naturally attracted to calcium. So it goes through your body. What they put in tap water is sodium fluoride. It lets go of sodium and attatches to teeth and bones! I don't know if it ever lets go:( but the stuff in your tissues definately leaves. I'm an example of someone who couldn't sleep, and now I can, even taking a long bath once or twice a week (sitting in fluoride.)