When to defoliate During Flower

[Techs221]

My plants are entering week 2 of flower when should I defoliate them and do I remove all the fan leaves or about how many fan leaves do I leave on the plant
Here are pictures of my 4 plants they have a pretty big canopy, These are also growing DWC

 

[Imzzaudae]

Real nice plants! great job so far!
From the pot up. Everything off 1/3 of the way up. She will continue to stretch for another 2 weeks maybe 3. Keep feeding her same as veg.
Add a little flowering mix if you like. Those big leaves are light collectors for your plant. Don't take them off just yet.

Have you checked for balls?

In about 2 weeks you should see nice little buds forming.
This should help you.

Strip to the tip

 

[cannafarmer420]

When you feel air flow is poor, any leaves not getting light and dieing all subjective