soaking oats and other grains

I hope I can get an answer here.
When I soak my grains, beans, and flour I'm supposed to add an acidic medium (whey, yogurt, lemon) in order to bring the water to 4.5 or 5.5 pH.

question #1:
If I use acid water (from my alkaline/acid water machine), can I not add lemon or whey????

I don't do dairy, and the lemon gives my oats a little too much tartness.

question #2:
I understand that the phytase enzyme in wheat breaks down the phytic acid, so I don't understand what the pH water/acid medium has anything to do with breaking down the phytic acid.
Is it the acid that breaks it down??

I'd love some clarification on this. Tweet