You don't need to add nutrients if you just re-potted with Miracle Grow. MG has nutes in it already, and they will last for up to a month.

Are you checking the weight of the pots before watering? The soil might be dry on top, but still wet near the bottom. Droopy leaves usually means over- or under-watering, and crispy leaves starting from the edges and moving inward is usually nute burn.

You will need to get more light also... you need minimum 3000 lumens per square foot, I'd aim for over 5,000...

http://www.planetganja.com/highsocie...ead.php?t=8778 <-- that might help too (if it's working ATM)