Well i ainty really sure mate.It's just they seem to do well in my cupboard downstairs.then when i put 6hem in my grow room in the attic they seem to g backwards.the temp sits at 80 lights on.60 lights off. i have co2 and a carbon filter fan which i have restricted a bit because i felt it was just a bit to strong.i have grown really good crops in the past and the only thing i changed in my room was that fan,and the last two crops i lost.i put it down to humidity but i'm open to any suggestions mate.