High Alk, Low-ish PH help!

Hi everyone!



Getting ready to do a water change and noticed my alk seems high and ph has been low-ish (going as low as 7.89 at night).



Info:

125G

Temp - 80

PH - 7.98

Salt - 36 ppt

Ca - 410

Dkh - 11.8 ish

Mag - 1200



How does everything look? I've seen that 8 dkh is the ideal range. Will doing the water change help or should I be doing something different?