The pH levels of water are to measure its acidity. Drinking water should have pH levels between 6.5 and 8.5 to be safely consumed.

Pure water has a pH of 7. If the pH levels of water is less than 7, the water is acidic or soft. Low-pH water can cause pipe corrosion while it travels through. It also tends to have a metallic taste.

If the pH levels are greater than 7, the water is alkaline or hard. High-pH water water tastes a bit like baking soda because it may contain various minerals. In general, drinking water with slightly high pH but within 8.5 is good for health. For more information about the safety and regulation of drinking water, check
http://water.epa.gov/drink/