Alkilinity should be 8-12DKH, 125-200ppm, or 2.5-4 meq/L depending on which units your test kit uses.
If alk is low you need to dose buffer to increase the level, you buy premade buffers from the LFS or you can make your own from baking soda and baked baking soda mix 6:1. Mix 6 parts baking soda with 1 part baking soda that has been baked in the oven at 350 for 2hrs. This solution will make a balanced alkilinity buffer that will have a minimal impact on your Ph.
Be sure and test your calcium and magnesium and dose them accordingly as well.