What do you mean? Water is at a neutral pH (around 7) unless you add something to it. But the highest pH that anything can be is 14 (very alkaline). The lowest pH something can be is 0 (very acidic). Each number is 100 times more basic or acidic than the preceding number, e.g. a liquid with pH 9 is 100 times more alkaline than a liquid of pH 8. And a liquid with pH 3 is 100 times more acidic than a liquid of pH 4.