ALKA seltzer - between it's name and the fact you said it LOWERS acid, you made the connection for me between ALKAseltzer and ALKAlinity.
I add ALKAlinity Increaser to my pool when needed, acid to lower it, (mostly to lower PH) which is closely related to alkalinity.
My 10lb bag of ALKAlinity Increaser is Sodium Hydrogen Carbonate, PH Increaser's the same w/o Hydrogen.
What's interesting is I take Vitamin C 4 to 5x/day to make urine acidic to fight UTI's since spinal cord injury 23yrs ago. Was discharged from NYU/RUSK this way and surely will continue it.

btw...1 adult aspirin at bedtime's still working excellent for my sleep time leg jolts & the stoma/bleeding issue seems to have adapted.

Alkalinity Seltzer