White Spots Dwc First Grow

[King Ally]

what are these spots on my leafs it's only on the one leaf but I had left the plant for 3-4 days this week & once I was able to check again it had grown a lot but also was touching the light so it might be that but ain't sure so what is it Lool ??first grow too :)

 

[Saint Skinny]

if its only one leaf, I wouldn't worry about it. I suppose it could be light bleaching if it was touching the lights, but it could also be salt residue from a splash of water when you were feeding.