ok.. I jsut tested my PH level in my fish tank and it's yellow. That means it's either 6 or below cuz yellow is as light as it gets on the chart. I'm assuming this is not good for my painted glass fish. They've been living in that condition for a while, a few month (since my last water change). so.. my question, how do i raise the ph level safely with all the fish inside? will adding aquairum salt do anything?