Quote Originally Posted by Hempsouth
Try dropping the lights down about and inch or two, with your fan heat will not be an issue.

Weak light can cause yellowing, but yours are not stretching which is weird, normally when the light is defficient the seedlings stretch and fall over.

A real weak dose of nutrients will not hurt them at this stage, like 1/10 strength.
Keep in mind they are not in the Hydroponic system yet, would mixing the nutes and pouring them over the rock wool hurt them?