You must add the appropriate amount to the mixing bucket after the mix has stabilized, and aerate strongly to bring the pH back up before adding to the tank.
Do NOT add Muriatic acid directly to a tank with living creatures.
Long term, I'd be looking for a different salt mix with lower Alk.
I just want to record these calculations in their own thread to refer back to in other threads. When alkalinity is too high in new salt water or in a display tank, acid can be used to lower the alkalinity. You can easily use muriatic acid (hydrochloric acid), or sodium bifulfate (e.g...
All the above seems extreme measures for what i assume is a new reefer albeit to the community try find a salt mix that matches your dkh requirements and perform water changes 15% till the dkh reduces