transplant shock or over watering?

Hi all...My plant is over 3 weeks old now and growing well finally. I transplanted it yesterday to a bigger pot and used fert for the first time to try and help the move go smooth. I added 1 tablespoon of fish elumins to a gallon of water, its 5-1-1. I gave it a generous amount. I have a moisture meter and it is at about half at various depths and locations. Today the larger and older leaves are darker green and drooping or curling a bit downwards. Any ideas?
thanks a bunch. i can post a pic if needed.