Stunted growth and lots of yellow?!? HELP

I'm not sure whats wrong with this plant. it is not behaving the same as the big girl 'Stona Lisa.' I have givin them water at the same time, same light, everything. Is this little girl getting too much water? too much heat? my humidity is low but wouldnt that cause problems for both not just one? any heads up would be nice. I dont want to get down to just one plant so help me save her! Using a 400w MH right now about 18" away by the way. She was like this before when still using CFLs.

what soil is that?

It's just some Sam's Club soil. says .16-.10.-.10 ratio on the bag and feeding for 9 months. But im switching them to FF Ocean in less than a week when i transplant. I just needed to use what I had at the time. 2 of my other seeds sprouted but then rotted out on the inside of the seed. Could this all be from the soil?

They seem to be drowning.

Bad seed you got there. The small one is dead.

That was my initial thought. But the big one (Stona Lisa) was dryer than hell last night and it had been over 4 days since their last watering and the litttle guy was starting to turn green again so I thought I was good to go. But just a few hours after watering it started going back yellow. Is there any way I can dry out the soil faster than normal or anything? Does it look like it wont come back?

If it happens after you water it's probably the ph level of the water. Check it and see