For a pool with a PF of 4.3 (yours!), 1 gallon of 8.25% bleach (typical Walmart concentration, currently), containing about 0.6 lbs of chlorine gas equivalent, would add 4.3 x 0.6 ppm free chlorine to your pool . . . or 2.6 ppm FC.

Bleach initially raises the pH a bit, but after the chlorine is consumed, the pH drops back to the original value.