curling leaves

[night501]

ok i have a belladonna in a general hydroponic water farm using only bat guano teas for my nutes. im under 2 40w cfl's for 18/6.
now the leaves are starting to curl into themselves like a book, there is no discoloring or anything else diffrent but i have no idea what it is and i cant find anything like it in any other threads. please help.

 

[scrumboldt]

to what portion of the plant is this problem relegated? is there also stretching? are the leaves also drooping? check for root rot. an iron deficiency causes leaf curl, but only when necrosis is present.