I'm a beginner but I've done A LOT of research
In my opinion there's a few things you should look at
Could be rare potassium overdose causing calcium lockout -- my first guess
Are you sure its not heat stress?...even tho temps look good, light can still be too close
Or it could just be calcium-magnesium-maganese deficiency in which u would wanna go invest
In some cal mag.
Well that's all I have to offer, look into the calcium lockout by potassium tho
Ill be checking back in here so keep me posted
Which plant are you referring to?
the dwarfs damage stopped spreading after the flush, so it definitely couldve been calcium lockout and the flush helped.
if youre talking about the skunk it could also be some sort of lockout, or some sort of overdose but ive been feeding GH-FloraBloom which is 0-5-4 and ive been using at half strength. Unless theres a lockup of nutes in the soil and roots i doubt its overdose.
about lights being too close i doubt its this on the dwarf, with it being smaller its always been 2ft or more away from the light. The skunk is about 18 inches away and the damage is to lower leaves, i doubt light burn would cause the kind of burn im having on the skunk which is at the tips only.