dont be afraid to give nitrogen in flower, its a myth(a very very popular one at that). You want to keep the fan leaves(bigger the leaf=more photosynthesis and it gets more and more effecient at giving your buds tons of energy to put into the buds btw .) that make energy healthy and making energy. i give veg nutes in flower every so often. alot of people will say "oh thats normal for the leaves to be yellowing and dying", that does happen and is normal BUT in probally 80% of the cases imo that i see on here people just let them slowly die prematurely and assume it is just normal yellowing.