Borax raises pH with little effect on TA. Baking Soda and Washing soda raise TA more.

Adding acid directly reduces pH and measured TA. Aerating causes dissolved CO2 to leave the pool water. CO2 in solution is acidic hence pH goes up.

The amount of acid required to move pH changes with other factors (TA among them). Try a quart (guess, don't measure) let it mix and see where it gets you. Don't go much lower than 6.8-7.0. Have you read Using Muriatic Acid to Safely Lower Your Pool's pH? If not, please do. It will take less acid to move pH as TA comes down.

It will take a while. Be patient. Aeration helps.

Happy to help.