How much Muriatic Acid can I safely add....

Jul 1, 2007
NW Minnesota
was wondering how much muriatic acid I can add to my pool at one time and on a daily basis.

I have High alk (280) and I am trying to get it to come down. PH is 7.4. How much would the daily amount be and how much can I add at one time? What is the best way to add it? Pump running or pump off? My pool is about 3900-4000 gals.