Diagnosis required

man i love this place.....

Thanks hasta for the last tip, it's one I'll bear in mind in future.
I started using the UK420 forum (no offence guys) so haven't been back here recently, so I thought it'd be courteous to let you know how it went on. I'll attach a couple of pics and you can see for yourselfs, but basically, whilst all the fans leaves browned and died, I still got some very pleasant bud!
My next lot have started flowering (although 3 had to go outside as they started hermying - I think this was due to going into strongly fertilised soil too soon as they started growing double branches straight after they were potted in it) and they're starting to show the same symptoms. I've given them ferts and Mg so I don't think this is the problem. I think therefore that hasta was on the right track.
As he says though, it comes down to practice and patience so I'll keep plugging away until one day I get it susses!

Following the above post, here's some pics of a new plant. Note the limp lower leaves (show no sign of discolouration/necrosis) and the necrosis starting around the viens on the upper leaves. Any suggestions anyone? My next try was going to be up the ferts/Mg or try Fe. There's not a lot I can do about the airflow, but I'll make sure she's watered properly from now on (per OT1's schedule on UK420 ;-))
(Pics to follow in next reply- having trouble right now!)

(I hope)

A couple more

Heat stress in my latest opinion of this problem.

i think what you see now is because of how much water you are spraying on your leaves. the burns appear to be on points of the leaves where the water collects (in the veins and the tips). this could be for one of two reasons either the water drops are acting as magnifying lenses and the lamp is burning them or the plain water has some sort of residual that the leaves find irritating or perhaps the pH of the residual is having a local effect on the leaf tissue. hope this helps you. it looks like you are doing pretty well for not being an expert. good luck you'll be one soon!