I would like to first of all thank everyone who replied to this thread. I've taken all of your advice into account and I appreciate the time you've taken to help me out.
I will make a more detailed and proper update post later. Life has been busier than usual.
As of now, some of my plants have been showing characteristics that I am finding difficult to diagnose and treat.
The other plants have been doing much better, thanks to the advice that I receive from everyone here and elsewhere.
For purposes I will get into later, I treat some of my plants different from the others.
The below plants are the ones that I am finding difficult to diagnose and fix.
These plants were overfed and dry. They had nutrient burn as attested to by run-off tests.
Here is some relevant history:
January 4, they were flushed but not enough because their run-off tests a while later showed that their PPM/EC was too high for the stage that they were in (Some of them had EC 2.5 or 1750 PPM!)
January 7, one of these plants was given a 600 PPM fertigation and its run-off tested at 1320 PPM!
Therefore, they were flushed more thoroughly on January 7. (I fear that it was a bit too thorough).
They received about two gallons of low Cal-Mag'd (580 PPM) and appropriately pH'd solution each. They are in three gallon containers.
It is now the end of January 13, and this is how many of them appear. I have some other strains in there and they are doing much, much better than the rest.
I gave them a bit of fertigation today at 800-900 PPM with pH 5.8 - 6.0. The pots were looking too dry.
Why are the leaves showing strange characteristics such as edges curling inwards, and heavy droop?
I can understand that the droopiness may be from overwatering. It has been several days now, and the droopiness is still present. I am a bit concerned.
Have you guys seen anything of this sort before? I and I am sure others would love some light on this issue.
Speaking of light, I am beginning to suspect that my lights (LEDs) are a bit too close to the plants. I will provide a more exact measurement tomorrow. Could this be light stress related?
Have an awesome day!