Quote Originally Posted by Rusty Trichome
You've got a hell of a lot lot longer than a few weeks left till they're finished.

That isn't heat burn, it's nutrient burn. Never leave nutrient solution on the leaves. Especially with an HID light pushing the envelope.

Old leaves are old news. Keep an eye on new growth, as the old damage will never 'heal'. Leave the leaves alone. Don't remove the damaged leaves, the plant isn't done with 'em yet.
Thanks for the advice, but it's 100% not nuitrient burn as I haven't used any nuitrients. Both plants have the exact same soil. It's 100% burn damage.

I haven't touched the leaves and I have noticed some new growth, not a lot though.

According to the details of the plant, there's only 3 weeks left...