Help drooping leaves here! 1st grow

Working on my 1st rubber maid grow here, I noticed yesterday that one my baby's leaves was looking a bit saggy. I have them on a scheduled watering cycle, No nurts given yet, about 20 days from seed, this is the only one that's looking like this, Ive looked through a lot of threads and haven't found anything like this yet so I decide it would be better to just ask before it was to late to correct my problem if its one at all ...

Thanks for the help

What's the temp inside the rubbermaid?

What is ur watering scheduale like, it could be to much watering or to lil watering or maybe is not enuff light? its out of those 3 things

Thanks for the responses. The watering cycle is every other day at 9pm, I let them dry out to about 2in depth of the pot (to touch). I have them under 4 cfl 5500k each bulb, as for the temp its around 72 during lights on and around 68 during lights out.

read thru this thread....you'll more than likely find the answer to your problem here.
https://www.rollitup.org/marijuana-plant-problems/150004-plant-moisture-stress-symptoms-solutions.html
there's even a pic on the first page of somebody's plant(s) that look just like you describe.
btw....i've found a better way to determine when they need water is by picking the pot up and feeling the "weight" of it. you'll get a better feel for this as time goes on.