Leaves turning brown

[Davidgris60]

I have two plants growing in my tent, supposedly same strain. They have been subjected to the same nutrients and light schedule. One is very healthy with no defects. Ther other has leaves on the buds that are turning brown, curling, and becoming crispy (see pictures) Lights are over 12" away. Can't understand why leaves are dying. 7 weeks into flower. Besides the browning leaves the buds look healthy. Any advice? Thank you

 

[SoOrbudgal]

Is the fan blowing on them and how hot is it? Does appear to be a soil issue almost bud rot check real good for bud rot or stem molds.

 

[Canuck147]

They're turning brown, curling and becoming crispy cuz you have them laying against your tent walls.