The alkalinity and ph in my tank are both low -- around 7 and about 7.0 - 7.4, respectively. I added an air stone to improve oxygen uptake but that didn't make any difference that I can tell. I recently added some Seahem Marine Buffer to increase both. However, I have read that I should not add a buffer. However, I have also read that adding baking soda is okay. What is the specific reason that the buffer is not good.