I just read the wonderful "pineapple juice solution" by Debra Wink. Wow. 

I have a question that the chemists or biologists on this site might know the answer. 

Wikipedia states that the ph of soda water is between 3 and 4, due to the formation of carbonic acid.

Would it work for the initial hydration of starter?

Would soda water work instead of pineapple juice? I am guessing that the ph rises as the CO2 bubbles off? 

Many of the store bought soda waters have buffers added, so probably best to use home made. . . 

Seems like it would be perfect. . . 

I will give it a try, but I am a relative nooby, so won't have a whole lot against which to gauge the results.