Help, my girls are burning up

I need some advise. My girls are 4 weeks into flower, beautiful NYCD. They started to show small yellow'ish burn dots. they start off a couple at a time then spread, on same leaf, till the whole leaf is covered then looks like they are burned up. I have rinced with clearx and they have only gotten worse. there are three plants in the back of the room that haven't been effected. :pimp:

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http://boards.cannabis.com/plant-pro...anted-one.html

SMG