Very hard to say. Use per instructions. Yeast nutrient /energizer from Wyeast should be added 1/2 tsp.(2.5 grams) per 5 gallons, but that is for beer. While apple juice is low in nutrients (Nitrogen) I add 2 tsp. (~10 grams) per 5-6 gallons. Try to find DAP (diammonium phosphate) +thiamine,+Vit...