Just start over, don't give anything but water for at least the first 2 weeks, looks like it burned up from fert, your temps are fine, maybe the MH light was too much for it? looks pretty small for 4 weeks IMO
4x5 Reviewed by 4x5 on . Emegency man..plant about to die, brown shrunken dried leaves. What to do??? my plant is about 4 weeks old and was extremely healthy until a day agot when i noticed light green-brownish color on the leave and began to dry up and shrink. i water it often but not too often and i've been using Foxfarm Grow Big and Big Bloom with every other watering. to save electricity I would but the small plant outside during the day and then for another six hours under the Metal Haloid Light in the closet. keep the humidity 50 to 60 and the temp. at 80-90 maybe too hot! whats the Rating: 5