Are the upcurled leaves a signal of too low humidity and too much evaporation and not necessarily a def/toxicity thing?

I assumed as much a few days ago and tried to increase humidity, move the lights away and I did move the fan as well...

They all get watered differently. The two healthy ones tell me when they need it (slight droopiness and dry pots). These ugly sisters have just been getting flushed as of late and haven't been in a healthy watering cycle for a while now... Like I said I have been doing the flushes with calmag'd water, but I'll try just plain next time (2 so far).

I'm going to let the problem children dry out and then a flush/dry out and transplant.

Thanks for the help....