Droopy leaves all of a sudden?

I am about 3 weeks into my grow and the leaves have just started to sag downward on my one plant. I am running an active hydroponic system and I have the pump on a timer set to go for 15min intervals, 6 times a day. 5 during light on, 1 during light off.

There is a fan inside and the temperature teeters at 80 +/- 1 F.

On my other plant, it appears the leaves are starting to curl at the sides yet they point upwards.

Could it be pH? Overwatering? Too high of concentration of nutrients?

Need some help from the pros!

Thanks

Drooping leaves sounds like overwatering to me... Back up off the water for a few days and see what happens.

well after a day with no water, the leaves are 10x worse. now they are touching the ground on both of them. Do you think leaving the light on 24hr for 3 days could have affected it? I dont think it should have...