I think they are curling like that because of the heat coming off the light. I will just use water for a while and see what changes. One of my flowering clones is going though some shit right now. i don't know what is wrong with it so I just flushed and now I am going to cut back on the watering. I wish i had taken a pic. The leaves are wilting and turning a darker green, with burns on the top of the leaves. . .