well i keep the temp at a good 75 80 it vary's on different days but i have actually two fans in there i just took them out to take the pic one in the front of the door and one in the back corner blowin the cold air in but i have one light its 100 watts reveal lightbulb with the enhanced color spectruim putting out 1260 lumens but thats about it i gave them some fert like a week ago and they started growing yellow tips
Like buds said +1)
With adding more soild to the stem.
But here's one of your problems.
First off, your plants are stretching to much to get the light. That's why they cant stand up on their own, plus your getting a lot of spacing between your nodes. This is because of two things since there still new to the world. You need more blue light, run some 6,500k bulbs if your growing with florescence's not just your red spectrum (2,700k) or so.
Red spectrum travels longer to get to the plant, that's one of the reasons they stretch. Next, lower your lights closer to the plant. Lower it as close as you can get before the temps get to high and before it starts to wilt and burn them. When your plants grow long and lanky like yours your not running enough light close enough to them.
Second your plant is starting to burn at the tips from the nutes you gave it. Hold off on the nutes for a watering or two and give the soil a good flush. Next time you give it nutes water it down some more. You shouldnt have to give it nutes until the 4 week or so depending on the soil you use once it pops from the soil.
How can you fix this grow.
1.) Flush the soil
2.) Lower your lights and add more Blue spectrum
3.) Once the soil hardens a bit I'd trans plant it into a bigger taller pot. You want the soil to come up to about 2 inches from the 2's set of leaves. What this will do is turn the long stem you go going on into roots.
.4) Add a shish kabob wooden stack into the ground just a bit to brace the plant until it can hold it's own.
You grow will take longer to finish but all hope isn't lost for this grow!