Your plant is showing classic magnesium deficiency. This can be caused by lockout or incorrectly mixing nutrient solution. To fix the plant…….Use epson salt, 1 teaspoon mixed with 1 gallon of water. Spray this directly on your plant soaking the upper and lower leaf surfaces. The plant will absorb the solution through the leaves.
Now you must stop using the
calmag product. Excessive calcium can lockout magnesium in coco coir! I know, same issue last grow.
I suspect your PH of nutes is out of the correct range also. Coco coir works best with nutrient solution adjusted ph to 5.8-6.3 for optimum nutrient availability to the plant.
I suggest you mix your base nutrients first. Then add your epson salts last. 1.0 gram per gallon of nutrient solution. The reason for this is if you add the epson salt ( magnesium) or your
calmag product to the water first, the Garden nutrients will bind with mag or
calmag product and precipitate out of your solution and form a layer of fine particles on the bottom of your reservoir. This is white or brownish fine powder. If hand watering the powder will build up in the coco coir. Especially if you dont water to runoff of 5-10% of nute solution. Runoff removes salt build up.
Finally you must PH check your nute solution!!! This is always done last as the starting PH is moot. The nutes will change the ph anyway. Final PH is what you want to know. This is critical when growing cannabis. PH of 6.0 is the Golden Standard for successful cannabis bud production!!
I hope this helps you. Just a note all the information I have shared with you is from Ed Rosenthal. I bought his complete Cannabis growing library and it has all the answers you will need to be a successful grower!!
Peace my brother!!
