flowering pics ?

here is few pics of two larger 6-7 ft.plants in containers, in between 5th- 6th week of flowering, so still 3-4 weeks to go, fan leaves started yellowing just after flowering and has got worse as flowers get bigger is this something that i should worry about or normal, i know i have read that some yellowing is expected but these 2 plants probably lose 6-8 leaves daily, i was kind of wondering is it from flowers size and trying to supply the flower, cause i have 3 other plant same size container, same care and they are not yellowing like these 2 plants that are same strain, other 3 have nice flowers but not large like these 2 plants