Strictly speaking both borax and soda ash can raise T/A too. But soda ash will raise it more. Normally, as pH goes up and down it changes the T/A as well. But, by adding soda ash, for any give pH, the T/A will be higher.

If you want to raise your pH without raising your T/A, you have a 3rd option: Since your pH is 7.2, if you aerate your water your pH will rise cost-free without adding anything and without raising your T/A. You can aerate by leaving it uncovered, by pointing your return eyeballs near or at the surface, adding a small fountain, or just leaving it uncovered with the pump running. A crowd of kids works too, but only if you are convinced your water is clean of contaminants.