Help seedling appear to be sickly (yellowing, red tips, purple stems)

Hello all, glad to be a member on this forum, and hoping someone can help me. I currently have 5 seedlings growing at approx 2 weeks of age. They have been growing fine up until a couple days ago when I noticed them starting to yellow, and the leaves are a light green, not a dark green. Also I noticed dark red on the tips of the leaves, and the stems of all the seedlings are purple. The leave themselves seem to be dry and not very lush. My concern is the plants have appeared to stop growing and I have been unable to specfically find out the problem.

My five guesses would be

1) The miracle grow potting soil might have too many nutrients for my seedlings? (I was planning to get something alot better when I transplant)

2) The temperature at night in the grow area can be in the lower 60's. I have the seedling encased in a cardboard box with foil to help contain the warmth.

3) Some sort of nitrogen deficiency already? This is what the plant abuse photos show. Maybe since it is cold, the plants are not receiving the proper amount of N?

4) Overwatering, or poor draining soil has stunted root growth?

5) Poor genetics, I used bag seed as a trial run.

If anyone can help me out I'd greatly appreciate it.

E-indoor
E-soil
CSL-miracle grow potting soil
E-bottled water
E-2 weeks
E-3 27w cfls, within 1 inch of plant
E-mid to lower 60's
E-semi humid
E-24 hour light cycle
E-well ventilated

things that jump out to me is that your soil is too hot for seedlings. also lower 60s is pretty cold and will make those stems color. flush the soil with some ph water to get those nutes out

Yeah, after I had already planted the seeds and did a little more research I found out how poorly rated MG is. Do you think that the controlled release fert within the soil over nuted my seedlings? This would make the most sense since they are different strains, yet sharing the same problems. I will flush them out tonight and hopefully they will perk back up.

Any other input is greatly appreciated. Thanks.