You can use 20 Mule Team Borax or Arm&Hammer Washing Soda (both in the laundry aisle at your supermarket) to raise pH. I wouldn't add more than a cup at a time of either, wait a couple of hours, then test pH again. If the pH isn't in the 7.2-7.8 range, add more.

Also you can add another 1/4 cup of bleach, and test the chlorine when you test the pH. If it's still low, add more bleach.