What's the problem? Flowering, PICS!

What up RUI. I am growing some OG kush, Diesel and super bud. Some of the plants are getting some crispy leaves, but others look perfect and are having no issues, kind of make me wonder because I am feeding them all the same, this has been happening for about 2 weeks now and getting worse:





My setup:

9/9/11 swith to 12/12, with three weeks veg
2 600W Block busters
3 gallon smart pot
6.5 PH water
RO water
roots organic soil
roots feeding sch 3/4 stenght
Tent temp 78 lights on 70 lights off
I feed once a week or every third watering.

I am stumped, help me out here guys! Much love.

you may be feeding too often, or may be feeding too much.

I c your lady near harvest time.
Its too hard to say to have not enough nut.
If u can take pic without your light with your flash on camera
I didnt c what color is your burn like?!
Best regards

It started yellow with brown spots then it just got worse.

Your pic is weak. I think i see some chem splash and nutrient burn for sure, and even if your feeding it the same your roots could be locking up , give them a flush and start with correct nutrients
good luck
Loaded For Bud