to much nutriens
mid flowering stage P = 200PPM
Late flowering stage Max: 200-400PPM
that is te recommed
and the new research is the all-time in flowering shape 240PPM
for in 1l water all unit
One blotch on one leaf is not a real issue..........no plant will ever have 100% perfect leaves, 100% of the time.
I do not think you have anthing to be worried about.
A deficiency will show up in many leaves all over the plant.