It looks like a nutrient deficencies most likely from PH lockout. The new growth looks Ok so maybe problem solved already. Those leaves will not recoverbut they are not gone yet. Just leave them to die off natural.

You may need some cal mag plus.

And filling out the trouble shooting form will get you much more help. Nice pic's they help too.
LOC NAR on probation Reviewed by LOC NAR on probation on . need some help i got this as a clone and it has these rust spots on it and i need a cure fast cause im goin 12/12 real soon.can anyone please help me find out what this is,and what do i do to get her healthy. Rating: 5