i did a search, just too much shit. and i couldn't find the troubleshooting guide anywhere. but... the very very tips of my leaves are curling up and not all the leaves are doing it. actually it seems that a couple of them have went back to normal. i had them away from the lights for a couple days, think thats what it was? also, how early can u determine the sex of your plants? when can i begin applying ferts, my plants r 2 months old. i have about 8 5 finger buds. and uh. i tihnk thats it. thanks in advance.
If it is the leaves at the top of the plant, odds are too close to the light. If they are the leaves at the bottom, odds are nutrient deficiency. You can begin fertilizing when the cotyledons (first, round starter leaves) have died. Sex is determined by either pre-flowers or when the light/darkness ratio reaches 12 hours each. Look for white hairs (for female) or clumps of balls (male) at the nodes (where the stem of the leaves meet the main stem).
The best sick plants guide: http://www.icmag.com/ic/showthread.php?t=11688&page=1&pp=15 Another good one: http://www.greenmanspage.com/guides/plant_abuse.html Plants should be fed at around week three or four. Yours are now overdo. Feed them with some 20-20-20 or 10-10-10.