Originally Posted by ashleynewth

hey ub. i've got a problem with a few of my plants and was hoping u could diagnose it for me. i suffered root rot last grow. i sterilized and started over from seed. i'm growing in pots with perlite with a pump feeding them twice a day. i regularly check ph and nutes. temps are 15c-26c. reservoir temp was 17c but i've just (today) installed heaters to keep it around 22c. humidity varies from 25-65%. heaps of fresh air. lights about 50cm from canopy. i've been using same nutes as always but started using dr hornbys big bud and hygrozime this grow. i am using cooltubes for the first time which has cooled the room considerably. outside temps have been very cold lately. i had a big bud plant with a few curled under shade leaves. suddenly one day all the leaves were cupped. i hacked it because i found a few suspicious looking balls on it earlier. suddenly a few other plants (all different strains) have begun doing the same thing. these plants seem to be growing more vertical than the others. the buds aren't fattening or as smelly either. i've read up on ur causes of this problem (leaf curl) but i don't seem to have any of these causes. i use polycarbonate roof sheeting as my drainage tray. a mate suggested this may be breaking down and poisoning the plants. another mate (a plastic injection moulder) said this was improbable because its u.v stabilised. its stressing me out. i've been growing for many years without a problem suddenly i cant seem to get it right. i am hoping it is just cold reservoir temps and i've already fixed the problem. please help. i've attached photos of healthy and affected plants. i've posted in this thread because moisture stress seems like the most common cause. cheers