cherry wine

I'm in the process of making a gallon of cherry wine (from sweet black cherries) and in checking the acidity I found that it was .30. In everything I've read it should be almost twice that.The recipe from Terry Garey's "The Joy of Home Winemaking" calls for 2 tsps of acid blend which was added before testing. I've also added all the other ingredients the recipe called for with the exception of the yeast.After adding an additional 4 tsps of acid blend in 2 tsps increments my reading has barely changed from the initial .30. According to the test kit 2 tsps should have raised it that much. What an I doing wrong? I purchased the test kit last weekend because I thought the one I had was the problem. Obviously it wasn't . My acid blend seems ok because after testing I can add some to the darkened solution and it will lighten. Should I add more acid blend at this point? I've yet to see a recipe call for more than 6 tsps of acid blend. Any comments or suggestions would be greatly appreciated !