Take a look at my plant in the pic.
It is showing very similar problems. Yellowing of the leaf tips, and then the tips become brittle and break off easily. This yellowing, and then necrosis of the leaves is caused by a Zinc deficiency in my case.
Zinc is the most common micronutrient found deficient.
First, younger leaves exhibit interveinal chlorosis, just in case you don't know what that means:
Chlorosis - is the condition of a sick plant with yellowing leaves due to inadequate formation of chlorophyll: chlorosis is caused by a nutrient deficiency, often iron or imbalanced pH.
The new leaves and growing tips develop small, thin blades that contort and wrinkle. The leaf tips, and later the margins, discolor and burn. The burned spots on the leaves could grow progressively larger. These symptoms are often confused with a lack of manganese or iron, but when zinc deficiency is severe, new leaf blades contort and dry out. Flower buds also contort into odd shapes, turn crispy dry, and are often hard. A lack of zinc stunts all new growth including buds.
This was the case with my plants. I have since flushed the res and added back new nutes. It has been a week and the symptoms are gone.
It could be something entirely different in your case. I just saw something similar with your plant that I saw in mine and thought I would offer this remedy.
Treat zinc deficient plants by flushing the growing medium with a diluted mix of a complete fertilizer containing chelated trace elements, including zinc, iron, and manganese. Or add a quality-brand hydroponic micronutrient mix containing chelated trace elements.
Toxicity: Zinc is extremely toxic in excess. Severely toxic plants die quickly. Excess zinc interferes with the iron's ability to function properly and causes an iron deficiency.
The information that I posted above is out of the book
Marijuana Horticulture by Jorge Cervantes. I hope this helped.
Peace and positive energy to you
