Hello, fox farm is a great fertilizer it does lack Calcium and Magnesium. A good espson salt should do the trick. The Grow Big is a good one for veg but i would suggest to add a seaweed extract. Make sure your not using miracle grow soil though if you are going to add your own nutrients. Try fox farm potting soil too works great mixed with coco and worm castings. O and the drooping of the leaves can be from temp, lack of water, too much water or your light is too close. As far as repotting i wouldn't change too soon, you can squeeze your containers and if they are really tight, time to transplant.

green leaves