Drinking natural alkaline water is generally considered safe, since it contains natural minerals. However, you should use caution with artificial alkaline water, which likely contains fewer minerals necessary for good health than its high pH would have you believe. Overuse may leave you deficient.
What pH water is best?
The pH of pure water is 7. In general, water with a pH lower than 7 is considered acidic, and with a pH greater than 7 is considered basic. The normal range for pH in surface water systems is 6.5 to 8.5, and the pH range for groundwater systems is between 6 to 8.5.
What are some alkaline waters?
Aquafina ranges between 5.5-7.0 (which is neutral or more acidic). Smartwater has a pH of about 7.0 (which is neutral). Evian has a pH of 7.2 (which is more alkaline). In the end, bottled mineral waters tend to be alkaline.