My plants are 3 weeks old (feminized jock horror), I'm growing under 400w hps, in soil, no ventilation and on 18/6. I'm growing in quite a big closet and I always keep the doors open when the light is on. The lamp is at least 40 inches away from the plants. The problem is that one of the plants turns her leaves upside down at the evenings. 2 other girls won't. I don't know if this is really a problem but I thought that maybe it is. So does anyone know what's causing it? If you guys need pics I can get them.