You can pour the borax right into the skimmer if you want or predissolve it. If you just poured it into the pool I would brush well to make sure it is all dissolved and mixed. wait 24 hours and retest. If the pH is still low add more.
Why is your FC so high?
If the alk is still low after you get the pH up to about 7.4-7.5 then add about 8 lbs of baking soda which should raise the pH in 30k gal about 20 ppm. You will probably have to lower the pH a bit after adding the baking soda.