Watch out not to voerwater those seedlings. With peat pucks, you aren't supposed to put the puck in soil until you actually see roots, and then, you should shred up the net thing because it impedes root growth. Your seedling area looks too wet; space those pots apart from each other to dry out better and add more light over them if you can.

The big plant is suffering from its tiny root system, and also needs more light. It will rebound; there's nothing SERIOUSLY wrong with it. Go ral easy on the ferts for now, and don't use any on the seedlings!!