One thing about ph that you have to be aware of is that, the farther you are from neutral, the more drastic the changes. Going from a ph of 9 to a ph of 8 is 100x as extreme as a change from 8 to 7. As the ph moves away from 7 (in either direction) the increase or decrease of ph represents an exponential change in water chemistry. So a ph of 8 has 100x as many hydrogen ions as a ph of 7. ph 9 has 1000x as many. ph 10 has 10,000x as many. ph 11, 100,000 times as many. And so on.
Someone should double check my math, but the basic principle is correct.