curled up leaves

Hi everyone, can anyone tell me if having slightly curled up leaves is normal or not in the first 2 weeks of growth and what its a sign of?

also i have 2 plants of which i do not know the variety, theyre on 24h cycle at the moment and are doing good but should i change the cycle at some point?
thanks

they might be better with a dark period, curling up leaves ussually means a deficiency, and down means an over fert. look in the plant problem section of the forum for some pictures that might help out.