My saltwater pool has low alkalinity (50) but ph is already on the high side (7.8).   Should I add some sodium bicarbonate to raise the alkalinity closer to 80 and then a day later begin gradual additions of Muriatic acid to get the ph back down to about 7.6?     Also,  I've been getting some skin irritation lately while chlorine levels are well within the normal range.  Could this be due to low alkalinity or does the water maybe need a shock treatment or?