Two good things about a gunite pool:
1) It can stand very acid water without melting the liner (vinyl is in danger once you go below 6.9)
2) It can stand VERY high chlorine levels, like 50ppm or more (where vinyl will bleach). This is good for clobbering algae but you still can't swim till it comes down to levels Ben recommends.

Now that your pH is high and your stabilizer (CYA) is zero, Trichlor tabs and/or dichlor powder is a good option. Both will lower pH and raise CYA levels.

But with Gunite, your cal is below the recommended 200-400ppm. Cal-hypo is a good chlorinating option for that as it adds calcium.

Personally, though, even with gunite, I'd worry about calcium levels last.

BTW, when your pH is at 7.6 or lower, your T/A will measure lower too, but it should be fine.