INDOOR CFL CURLING LEAVES, PLEASE HELP!

hi, i have recently started up a grow which was originally under a skylight in my loft.. it consists of 30 bagseed plants which were growing healthy but started to grow slightly too lanky and i decided they would not flower in time so i put them under;
1:60w fluorescent
6:20w cfls
(about 6 inches away)
the plants are about 1.5 ft tall and nodes are about 4 inches apart,
instantly they started growing outwards and less upwards... a feed however, the top leaves on about half started curling and going very shiny and 'greasy' looking and feeling.
they are not curling up at the edges but curling down and remember are becoming soft and floppy not dry... i am worried this could be nute burn or over watering which is an irritating dilema because i want to try to flush the nutes if its nute burn but dont want to over water yet more if thats the problem... their last watering was 2-3 days ago and the top soil is dry but sill slightly damp about an inch in does anyone know what to do??? will the leaves recover or shall i chop them off.. and the head?

thanks