Should I defoliate the yellow leaves or leave them on?

Leave them, the plant is drawing pre-made nutrients from them to feed itself during flowering. Only remove them when they are nearly dead/brownish. You would be surprised as to how much photosynthesis they are still able to do, besides, they are doing no harm. In fact it is more beneficial to leave them rather than remove them because they "look ugly"!

Wow thats a hot tent buddy. In order to photosynthesize its needs green leafs im afraid. it seems you have gone quite heavy on the defoliation here and your leaves being yellow is a lack of nitrogen in your feed which is also responsible for making your plant green lool. Defoilation can be good if used properly when i grow a plant and i know many other growers do this too. but its a funny subject. Right cannabis is one of the oldest plants in the world it has evolved over millions of years. if the plant would benefit from having the fan leaves stripped it would of evolved to do so itsself. Every healthy leaf you remove you are taking away all that surface area of leaf to create energy and in turn makes the buds alot fatter. If you must defoliate in flower I would suggest waiting until week 7 or somewhere later as then you will maximise the yeild and also your grow light :) just my opinion anyway buddy best of luck and if you need any help or advice hit up my dm always about :) keep it green buddy :D

Well, as you're past fattening. They really should of been removed after pre flower has ended. To allow light to hit the stigmata sites. Now. Really is there a point. U could remove the ones mid level. The ones at the end will be good source of feed,,if she needs more. So I'd leave them..

There's a few things here. Idk how long you've had these issues. As u said wk 4-5 of bloom. U cut the nutrients way to early when she needed a high PK and some N. Overall you needed to keep her on a general npk feed in favour of mid flowering. Check the trichomes. But, tat looks like its been showing it needed high pk and some cal. Really showing high signs of PK..and sadly now you're coming into the ripening phase. That window has passed. And the need to add high doses of NPK is too late. The big bud part phase has passed. But there's some good news. U might have some time to add thc in ripening..again if u still have a lot of clears. Id move on with a 1-3-2 or 1-3-3 Npk to help the ripening process..