Reducing TA takes awhile so be patient.
The process is to reduce pH with Muriatic acid and then raise it with aeration. Aeration will raise pH without raising TA. Raising pH with washing soda, baking soda or borax will also raise TA.
Do you have a waterfall or another water feature to aerate? if not, point the return eyeballs toward the surface.
We recommend washing soda and baking soda for raising TA. Borax for raising pH.