Deficiency?

nute shock I believe the seedling should adapt to your solution soon

I honestly would not say that is a deficiency, looks more like a small insect may be inside your tent some where going to your leaves to feed off its nutrition. When I discovered one of my leaves showing those signs (which I personally call bleach like spots or tie dye), I later discovered a small tiny spider web at the bottom of my tent in a corner and then eventually found the spider which again is not big at all more like a Nat fly size. Therefore it is best to remove your plants often to wipe down all sides, bottom, corners and roof of the tent to keep your babies bug free. Believe me ALL BUGS will find a way to get to those tasty Trichomes. Hope this helps.