What happened to my seedlings?

These used to be two perfectly healthy Nirvana Northern Lights seedlings:

Seedling 1:
http://pixpipeline.com/d/467d1d5ad089.jpg
http://pixpipeline.com/d/4227b21bdda.jpg

Seedling 2:
http://pixpipeline.com/d/617667312762.jpg
http://pixpipeline.com/d/1bf371e273fa.jpg

It's hard to tell in the pictures, but the cotyledons are an unusual, very deep green.

As I've killed a few seedlings in the past due to carelessness, I made sure to keep a close eye on these. Temperature stayed around 75 degrees, rockwool stayed moist, but not wet, with distilled water. I sprouted them directly in the rockwool, in a tupperware. I have honestly no idea what could have possibly gone wrong with these seedlings, unless I have a bad batch of seeds or there's some kind of undetectable pathogen in the rockwool itself.

Any ideas?

what kinda light do you have them under they are pretty sensitive at that stage.

3 23w daylight CFLs.

how far away are the lights ? how deep did ya plant them in the cubes?

Iuno, looks like the cube is a bit dry but it's hard to tell. I imagine they would be stretching more if it were a lack of light...

There's a chance it's your water - have you tested your PH or is your water especially hard? You might want to try feeding them with distilled+purified water.

The lights are probably three inches away, and I planted them probably slightly more than an eighth of an inch deep.

The cubes are wetter than they look in the picture, my camera just kind of lightened the color in everything in this picture. Hard to say what could have gone wrong here.