This seedling is NOT overwaterd. This seedling is NOT over-nuted (it hasn't had any). I don't think it's Mg deficient because it is too young. I don't think it got too hot as allt he other seedlings of the same strain are perfectly fine. It's in the same soiless mix as the rest and watered with the same pH water as all the rest. The only thing I can think of is that it got oo much light, but it's about the furthest one from the light and all the rest are fine. Any ideas?