3 cups of sugar to a 1 gallon batch and its fermenting, thats impressive in itself! If I were you Id dilute this down to like a 2 1/2 or 3 gallon batch by adding un sweetened apple juice if you can find it without ant sorbate or benzoate in it. Ascorbic acid is fine and actually is what I use when making light wines like this as they can oxidize (turn brown) very easily like an apple with a bite out of it for a few minutes. You really need a hydrometer to make wine especially when starting to learn how to make wine and the proper sg for a wine like this is about 1.085. get a hydrometer, they are very cheap and simple to use, you put it in the liquid and just read where it floats like a thermometer in your mouth.