How do you fix a chemical imbalance?
OK you've got it the wrong way round.
Alkalinity isn't quite that. It is "Total Alkalinity". To lower Total Alkalinity you must add pH Buffer.
Your pH is way way too low. To raise it, you must add Soda Ash. Confusing terms but that is how it is. Most pool shops offer free water testing so they will actually tell you what you need and how much.
It depends on what chemical your talking about. Chlorine, pH, alkalinity, or hardness.