Help??????????????????????

Hi People,Got this problem with my girls, the tops and middle top of the plant, the leaves are going bright yellow from the outside in and then later stages going totally yellow then dead browing(See pics for better idea!).The lower and outer leaves aren't affected as much just a little tip burn with slight yellowing on some leaves.
basically it looks like the area most affected is right under the lights!
Did i burn them under the lights or is this just a heat stress related issue?

Ive got them under 2 400w hid's and did actually foliar feed a week and a half ago....
To be honest the air isnt moving much which i will address.
Their being fed on canna aqua vega,soft water ,p.h-6.2.On a nft system(totally lightproof)
The temp is at 83.5'f and 35% Humidity.



Pic 1 =Lower outer leaves
Pic 2 = Closer to the Middle and the light
Closer
Closer

First i'd drop your ph to 5.6-5.8. Then I would ask you how far away your lights are from your plants. Third I might want to know if you foliar fed with the lights on and let them dry that way.

That would be what I would ask but I'm not getting involved... ;):)

Yeah lower your ph it looks like nute lockout

Ok weedhound, If i was going to answer the questions that you were going to ask but didn't because your not getting involved, these would be them. The lights are 24 inches away and yes the lights were on when i foliar fed. I'm thinking this probably wasn't good? Ideas on this appreciated??