Looks like it could have a possible magnesium deficiency.
MRDiff Reviewed by MRDiff on . Flowering 6th week Leaves turning yellow!! Help! Filled out trouble shoot Ok so just recently the flowers stated turning yellow on the outside. By looking at the pictures is this nutrient def. or is it over nutrients or is it because its too hot in the res. the temp hardly goes over 80 F? Any help please I dont want my grow to go to waste. What should i DO? What is your experience level? first time grower Your Equipment: .1) Type and wattage of lights. Using HPS lights right now 400watts .2) Distance from tops? On average about 6-8 inches .3) Reflector Rating: 5