Flowering Plant Food? Will this work?

Hi, I have two plants approx. 8 weeks from seed and beginning the flowering cycle. 31" and 29". I made a mixture of 1 gallon mineral water, 1 tbsp. miracle grow, 1 3/4 tbsp. pure cane sugar. Will these be and effective plant food for my flowering cycle or is it overload? Also with my plants the height they are just entering the flowering phase, approx. how much taller should I expect them to grow? ( Outdoor Soil, btw.)