I am not the one to give advise on this, but here are a couple of links, until you get an expert opinion.
Marijuana Plant Abuse
Identifying Plant Nutrient Deficiencies
Dreadscale Reviewed by Dreadscale on . leaf discoloration? I'm growing 6 plants under a 450watt MH in an ebb n flow hydro system. They're doing great- three weeks old, but I noticed one plant had a slight yellow discoloration on two leaves. The one on the left, and the one of the right. The one on the left is the largest and probably easier to spot in the pictures. What does this mean?? Thanks! :rasta: Rating: 5