If you never had any pH problems before, I would get a liquid test kit and verify the test strip results. I had the test strips for a short time when cycling my tank (much quicker to get an idea of levels), and they showed my pH around 6.6 or 6.4, but when I switched to liquid tests my pH repeatedly showed stable levels of 7.2-7.3
In the past I have added baking soda to increase my carbonate hardness (tap water here is less than 2 degrees kH), and it increased my pH. I just make sure that the pH is stable before/during/after partial water changes so there aren't any changes. I just wouldn't add it to the tank...if that is how you proceed add it to the water you are putting in your tank after a partial water change. Too much of an opportunity for disaster to add to your tank direct.