What deficiency is this? Or Leaf Burn?

Hi Folks
Today some of my leafs on my tallest plant are presenting some weird brown spots on the middle leafs, not even the tallest....Its a Bloody Skunk AF on ending week 5.... Is this Leaf burn (slight curling to the top) , I positioned my 1000W LED light a bit taller, about 18 inches from the tallest leaf and about 28-30" from the dirt level...

calcium def
need to feed it some cal/mag .... for whatever reason growing under LED's requires more cal/mag also if you are growing in coco youll need more cal/mag normally also

yes, looks quite similar