Have this GDP and Purple Kush plant in the mid/late flower phase.
Watered them both w/ 1 gal water last night since they were feeling pretty light. 12 hrs later I check up on them and all is well, 24 hrs go by and I see both of their leaves curling up and blackening.
It’s been in the single digits here lately so maybe the grow area got too cold for their liking?
What do you guys think is the cause? A deficiency or something environmental?
Everything in their environment has remained consistent and this is the first im seeing anything like this. I’ve been giving them Tiger Bloom and Cal Mag for the past weeks but have not noticed anything adverse.
I have noticed that the curled parts of each leaf is brittle to the touch. Idk if this could be an overwatering or N deficiency, most of the sources i’ve checked are saying those are the main culprits of this condition
Temp could do this. What are your highest and lowest temps in your grow space?
Been feeding anything else? Both of these are more like supplements and designed to be added with other bottles to form a complete nutrient package.
It doesn’t sound like you watered too much, but this is typical of an overwatering issue. Which is pretty much lack of oxygen to root system. I’m wondering if your watering didn’t just line up with cold temps and stressed or damaged root system.
It has been anywhere from 64-71F in the grow space depending on if the light is on or not
I have not been giving it anything else, I have the trio pack which includes Grow big, Tiger Bloom and Big Bloom.
Should i start incorporating Big Bloom or
look to supplement with something else?
The water is usually room temp, during yesterday’s watering it was slightly warmer. But it would make sense if the water had something to do with it either damaging or stressing the roots because it’s the only variable i can think of having been introduced in the past 24 hrs.
The cold temps outside have been around for the past few weeks and i haven’t noted any significant temp shift in the grow space
In a perfect world you would be warmer, but I can’t say temps you posted would cause issue that you have. Your plants are kinda late to get crazy with nutrients now. Perhaps if you measured your runoff ppm compared to your input ppm would give an idea of what if anything is going on there.
If you plan to continue using the fox farms nutrients i would download the schedule from their website. Pay extra attention to recommended flush intervals.
Magnesium excessive … looks like too me or cal deficiency…. Some type of nute burn . Idk but the buds looks good. I would do just water until she bounce back
I agree here. Looks like like a deficiency, and a bit like they got a lil too cool.
If I had to guess the deficiency id say maybe Potassium? But its not obvs at all. Like DB said, id be more comfy knowing your runoff numbers before recommending you increase it.
… looks like too me or cal deficiency…. Some type of nute burn . Idk 
but the buds looks good. I would do just water until she bounce back