IMHO, something just does not jive here..
You have a PH of 3.1?? Most wines fall in around that range of 3.3 to 3.5.
A PH of 3.1 says that your wine is rather acidic.
You then say that you have a TA of .35 (grams per liter, I assume). This is very, very low. Most whites fall within the range of anywhere from .55 to .75. 3.1gpl is saying that your wine is very SHORT on acid.
Confusing numbers and disagreements between PH and TA do happen. PH measures the acid's strength, while TA measures the total weight of the acid present. For grapes, there are differences, but not like this.
If you are sure of your numbers, I would think twice about adding any acid. According to your PH reading, it is the last thing you should be adding..