I'm no expert by far but I'll point out some things I see wrong first of all.

12/12.. you really need to be on 18/6 or 24/7. 12/12 is for flowering. Your seedling needs some light to grow upwards for at least the next 3-4 weeks.

Watering everyday? You should not be doing this, you want your soil to be moist, dry out for about the first 1/2" of soil and then water again. Typically this should be every other day at the earliest.

1 75 watt light? I didn't know they made a CFL equivelant. Really you want 2 lights for every plant minimum. You said you had 15 plants but only 1 light. This is another problem right here. I would suggest getting 2 preferably 4 6500K color temperature CFL's.

I don't see any fans in there.. get a gently breeze to help the seedling strengthen up. Nothing too strong, just nice and gentle at first.

It seems the best thing you could be doing right now is read read read.

I speak from expierence, I killed so many plants and had no idea what I was doing until I got a few things straight.

For me it was watering, PH, and proper soil. The more I learned the better my growth became.

Just read alot, and if you have a question use the search function before posting a new thread. Often times the question you have has already been asked, although some things don't show up in searches easily.

Good luck.:thumbsup: