ADVICE PLEASE

Day 51 from sprout. My Gold Leaf auto is about 2 weeks into flower...x2 of the other 3 have just started to flower...and the last (Northern Lights) is still in veg. About a week or so ago I gave them all a really nice trim below the canopy. I also thinned out a lot of the fan leaves on top. No signs of any nutrient deficiency. All in all they look really healthy to me. My biggest concern is how and when to defoliate and maybe I have gone too far? A majority of the canopy has filled back in since I gave them a trim a week or so ago. I'm on a 18\6 light cycle. Growing in deep water culture with recirculation... pH below 6 above 5.5. any tips would be greatly appreciated here's some pics to show you what I'm talking about!

Natural light pics help a lot

Defoliation is a choice that some understand and others overdo.

I simply don't. removing "food factories" from a plant, to make it better?
Nope, not in my book......

Here are some lights off images.

I wouldn't touch them until the stretch in flower is over
Then u know where the bud sites that need opened up are

Sorry... This last picture is my gold leaf which has been in flour now for two weeks and smells really good so far!