Do you know the reason for this leaf discoloration?

After I gave my plants some nutes (Grow Big from Foxfarm, 3/4 of strength based on their schedule), the next day this one leaf changed color and I dont know why, and the other leaf got some yellow color at the tips.
I think its nute burn but I'm not sure.

I'll appreciate your comments.

That looks like Calcium deficiency.

But only on one or two leaves out of 5 plants????