That does seem very low for alkalinity. I would do the test again to verify. Raising it slowly over time is the way to go if it is in fact to low. In my opinion controlling the change using water changes makes the most sense but ive never had to do that before. Im sure a quick search will give you some ideas. Anytime I see a test result that far off I question the validity. You may also want to test what your salt mix is mixing to for ph and alkalinity.
So far I have been getting my water pre-made from my lfs. I will definitely run that test again and also on the water from my lfs before I do my next water change this weekend. They both should show similar results since I've always used their water. Hopefully that will tell me if I need a new test kit or keep doing weekly water changes.