1 type of light (full service florsents cool white)
2 distance to leaf (2-3 inches
3 medium dirt, perlite/vermiculite, etc (p/V)50/50,, 25/75)
4 ph and ppm of ferts (600-1000 ppm over background)
5 ambiant temp(80-90 d.f)
6 air movement (leaves moving)
7 fert sequence if hydro (every 4 hr for 20 min)
Well that how to do it
Flush the hell out of them it also may be a fert lock up , and use drinking water for the next few days.
Thats if I was guessing how to do it.:dance: :dance: :dance: