How close do you put the bulbs? It seems only half that plant has a problem? Looks like it could be heat damage, as it looks the worst around the center of the picture.. and gets better as the foliage gets further from that point. Maybe I'm seeing it wrong.
the lights are about 1 inch away the lower leafs seem fine just the top 1's started folding like a taco i dunt think its heat burn or heat stress cuz i have a smaller 1 right next to it and its growing perfectly finee
I would worry about the color of ur leaves before the curling... Just put a temp. gauge in there to make sure ur temps arent too high, it looks like ur going to suffer from nutrient burn soon... are you feeding it anything as of now?
by mistake i threw in some slow release ferts i think when it was small so thats why it got the yellowin but the new leafs cuming out are fine just the folding it might be high temps..
damn son... i know this and ive never really had to flush until the end cycle... read around the forms, u can learn everything that u have questions to. But its normally 2-3 times the amount of what ur pots hold, water in gallons that is. So flush 2-3 times, and stop with the nutes!