plant not looking good

Have one of 7 that may need some help thinking ph headband plant...in promix ph is 6.1 to 6.5 had in 4 inch pot just transplanted to a 3 gal. was root bound ( molybdenum deficiency ) maybe from being root bound..fed with blue planet nutrients ph 6.5 see what happens

Catch that early, messed one of my plants up. It was middle of floser and turned whole plant dark purple by the end.

do I need to cut sick leaves or transplant in this case?

Oh leafy problem as usual. U maybe got a problem with your PH. Remove and discard all buds with bud rot carefully, as well as nearby buds.This is incredibly important if you don’t want to lose the whole harvest! Don't let anything any of the rot touch other parts of your plant. Remember, it's generally recommended to keep the pH between 6.0 - 7.0. Take care of your babies!

Must be hot in there with all those canoes.

what are your low night temps at?

temps light on 82 lights off 72 about.. plant still in veg just a update plant looking good now

Its not heat stress then
but it is stress of some sort.