Help my young plant is ill!

I have 6 new plants that are about 2 weeks old.I have recently transferred them from pete pellets into larger pots.5 of the plants are growing well but theres one that looks a bit ill.
The leaves near the base have curled right down and there are brown patches appearing on the tips.
Can somebody help me save my baby!!!!
Should i flush it with water? Maybe there are to many nutrients in the new soil?
I've tested the soil Ph and it seems fine so any advice is more than welcome please!
Many Thanks,
DrGreenthumb

Does this plant share equal priviliges with the light? I doubt there's anything actually wrong, maybe a slight overwater with some natural dying of the lower leaves. Brown spots may also occur through watering from the top while the lights are on. The water is boiled and cooks that part of the leaf.