Generally, the use of "dry acid" is not recommended on this site because it adds sulfates to your water. What's bad about sulfates Since TDS is well-established as a non-issue, I can think of two possible things:
1. "montezuma's revenge" - politely called "gastric distress", is usually pathogen-related but can be caused by drinking water with several hundred ppm sulfate, if your body is not used to it. High sulfate will also make the water taste bad (not sure about the levels required for this).
2. "gypsum scaling" - I don't know if this is even possible. It would involve CaSO4 * 2H2O (gypsum) forming due to high CH and sulfates. Technically possible I guess, but gypsum is about 15x more soluble in water than calcite (normal calcium scale).
Is there something obvious I'm missing? Seems like the water taste would be the most serious of these.