I have minor curling but no infestations. Any other ideas?
three things, first thing could be heat stress either its getting too warm in there or the lights are too close. second thing the temperature fluctuation between night and day cycle remember no more than 7 to 8 celcius between night and day. The third thing is if the fan leaves have ripples on them they are being stressed by the fans, turn them down a noch if this is the case.
if you can post a pic that will help. check ur conditions thats what most likely the prob is, just fix the temperature difference and ina few days they will be fine.