YELLOW Curling Leaves mid Flower

It looks like this is the normal yellowing you will see when you decrease the nitrogen and your nutrients during the flower phase. The leafs are simply using up all the energy that is stored in them. You will see other leafs soon yellow and maybe even change to other colors like purple, and then fall off. The plants look great!

Completely normal, you're on the right track, keep it up!

This is a normal behavior at the end of the flower period, i guess you are already started to flush right? The oldest leaves just start to fall of, but the rest is still nice and green, dont worry about nothing 👌😁 Please dont forget to mark my answer as solution if you think it helped you 👌😁

Super cool! Yellowing is normal when you reduce the amount of nitrogen and in the last weeks of flowering when you've done some kind of root wash or start to lower ppm. In my opinion, your plants look super good, you'll see how the buds at this point will start to fatten up and maybe in the future they'll require a bit more PK, but so far they look super good. Congratulations on your first grow! 👌