New grower, need a little help

[IslandGrinder]

Can somebody please tell me what's wrong?

I have 2 seedlings under a meizhi 450w led light hanging at 18" my water is distilled and ph'd to 5.9. Seedlings are in Promix organic vegetable and herb soil with %25 perlite.
One seedling looks great but the other one looks like this, any advice would be greatly appreciated!

 

[Calvados]

Recommended height for seedlings per your manufacturer and model is 24" - 30". Start at 30". Water when soil is dry. Make sure the sides and bottom get wet. This stage is all about getting your roots to stretch out. You can mist the leaves if you want.

 

[IslandGrinder]

Thanks for your help! I'll raise the light up as soon as I get home from work.