Wondering if someone could identify this deficiency

Hey all, hoping someone will take a crack at this one.

have you checked for mites?

I don't think it's any kind of infestation because it is one plant in an 8 plant SCRoG and it's the only one that looks that way. Also, the condition seems to be moving up the plant.

bumped to get it from under the pile, any suggestions?

That's a very early deficiency so it'll be hard to tell. Do your nutrients provide calcium? Is this all over the plant?

Phosphorous. maybe a hint of N too...

These shots are both of the same plant, which are the same plant as the ones in the OP. Well, just except that they are slightly older.