# Your tank of alkali fish needs a pH of 8, and the pH is 6 at present. What should you do to the H^+ concentration?

Decrease the ${H}^{+}$ concentration 100 times.
pH of 6 means that the ${H}^{+}$ concentration is ${10}^{-} 6$ M.
pH of 8 means that the ${H}^{+}$ concentration is ${10}^{-} 8$ M.
The current concentration is ${10}^{-} 6$ M which needs to be divided by 100 in order to get ${10}^{-} 8$ M.