Help. Dying Plant. Everyone!

I have one plant. I've been so excited because so far, everything has been going smooth and the plant is quickly growing. For the past 5 days, it's been on an18 hour light schedule. From noon to 6:00 a.m. I had to slowly work the plant into this schedule about 5 days ago because I was apparently not giving it enough light. Anyways, I had to work this morning and no one was here to turn the light on at noon. So I turned it on at 8:45 this morning before leaving. I came home about 30 minutes ago. The leaves are droopy. I'm worried. I really don't want this plant to die. Could the light have hurt it? I watered it last night before going to bed. I usually water every 2 days. Could it somehow be over watered. I need as many opinions as I can get to save my plant. Also please tell me what I could do to correct it? How could they have suffered so quickly? I've posted some pics.

Boy cried wolf...

There's nothing wrong with your plant. Not in those pictures anyway...

Why does the soil look so dry if you just watered it last night? How are you watering?

It was perky yesterday. Actually, it was perky this morning before I turned the light on. But, now the leaves look... Sad. The very bottom leaves are the worst. They're the droopiest. And they're getting a little yellow/brown shade. Not much, but it might escalate. Also, the next row of leaves up are drooping. The others are fine so far.

maybe its time for you to transfer it to a bigger pot

The drier the soil the farther the roots drive down the more water they stay up higher i say root lock

So you think by transplanting them they will grow properly again?

Number 1. GET A TIMER!!
Number 2. I think its time u should start with the nute solutions.
Number 3. Transplant the plant to like a big-ass pot.

This is Ganja... the most unpredictable plant. Dont worry, it wont die

All the best to u.

nutes...feed them...

nutes with a lil epson: salt 1tsp per gal..transplant too..

i see many ppl have the same opinion. do it. transplant and then start nutes. start with mild solution... then increase the dosage. study the plant.
all the best

omg!!!
what lights are u using???

I'm using two 48" tube plant lights. They give off a blueish/purple light. They seem to work great...

Also, I'm confused with the nute thing... People always say to feed them. I've spent many amounts of time trying to figure out the nute by searching this forum... Of the hundreds of thousands of threads, I haven't had any luck. I've posted my own threads asking, and every tells me I ask dumb questions, check the forum. Can someone tell me what nute solution to buy and how much to use... And how often. Please. Otherwise, I'll never get any nutes.