To restore pH levels, you can acidify the hair with a vinegar or lemon rinse.
Try this pH balance hair-restorer all-natural recipe:
Add 2 tablespoons of apple cider vinegar to 2 cups of warm water. This recipe can be used as a final rinse, or a next-to-final rinse.
.....Try the above recipe to restore the pH levels in your hair and you'll notice the change in your hair - more shine and moisture!