Thanks for the reply,

I haven't filled out the problem form as I'm way way way too hungover... no excuse but I'm dying here ! There are a few things it can't be: heat, humidity, air circulation, fresh air, bugs, over watering or under watering. It can only be the soil, I just don't know what it is...

This particular strain is different to the rest, it's either Chronic or Big Bang 2... I was also told that it isn't uncommon for the large fan leaves to start eating in to their nitrogen supply even at 4 weeks of flowering...

All the plants have had the same feedings and the other three are near perfect. I am noticing some leaves with burned tips so I think it could be an over nute issue.

I gave that plant a flushing just now so over the next few days I'll have a good idea what's going on. The buds are forming unbelievably fast ! The LED and CFL combo is blowing my mind !

I was nowhere near this amount of bud in my last grow, well, at this particular time anyway. I'll keep a close eye on the small bud leaves for yellowing... I was told that this is really bad !
I have noticed some of the smaller 6 inch leaves turning a light green.

So this is telling me it could be a nitrogen deficiency... I'm getting some mixed signals here. My temps are around 80F with the lights on and off they are around 71F.

I don't think it could be heat stress with those temps, and also I use 4 x 65 CFL which are 1 - 2 inches away from the plants, and my 190w LED is at a good safe height not to bleach.

I'll take a photo of a couple of leaves to look back on in a couple of days.

Thanks for the help

S.L.