?? How do u explain DWC then?? Plants will only droop from too much water when they arent getting enough oxygen (i.e they're drowning). This is from Over-watering and occurs in soil mainly, but would be happening all day & night, not just during the lights out period.It could also be caused by to much water, you don't really want to water them in there night cycle. If your watering them the same as when your lights are on this can happen as well.