nute burn

when you nute burn a plant will it get brown dots and curled up tips?
i thought i over did it with fox farm but now i saw in my book it looks alot like a potassium deficiency...but hey i really have no idea

room temp is ussaly around 82 but reaches 85 sometimes not too often... at night gets about 74

now i am starting to think it is fungus !
gah it is working its way up to the newer leaves.... and the bottom ones are all spotted with brown dots or curles.... is it fungus!? fuckkkk

pics would help us out. brown and curling tips can be nute burn. grey mould looks like grey mould. not sure what fungus looks like in this case.

over ferting can lock up potassium if you think you over did it with the nutes you probably did