I agree with Jan.

Furthermore, if your pH is 7.2, it's a feature of chlorine that it's more effective at lower pH--7.2 is better for fighting algae than 7.8--but the water is easier on the eyes at 7.8.

Your T/A is 80, which is the lower end of the acceptable range. Unless you are having troubles holding pH steady I wouldn't add baking soda. I also only add one pound at a time, wait a few hours and test T/A. It's always MUCH easier to add more and wait than to correct for too much. The ONLY exception is chlorine--you want to hammer the algae hard!