Was it dried out before you watered it? If you didnt let it throughly dry before watering, you over watered.
Its the most probable answer even if you dont think it is.
What changed? You added water.
Lights didnt change, temp didnt change (unless cold water?)
I always let my container get dry, and a tiny bit of droop to the plant. Not much, i really mean only a tiny droop, i check the plants several times a day so im sure to not let them dry for more than a hour or so. It is important to let them dry though for proper root growth. If you over water you will have a very shallow and weak root system vs letting them dry, and that translates to a much larger and more vigorus plant.