ph of fresh must

[winophite]

I'm using my buddies concords for a wine making try and have just prpared the must. My question is about ph and how it relates to titration test with a "parts per thousand on the tartaric scale", which should be 6-7 for average. My available ph meter reads an apparent different scale, reading 3.29. So... should I add extra acid blend prior to fermentation or not. My starter yeast solution is ready!