Bhut Jolokia leaves curling

[johnnyfive]

Hi.
 
I have these 2 bhut jolokias that are growing quite fast but they have these leaf curling symptom that I can't seem to fix.
I've tried to reduce temperature, watering frequency and add calcium. Nothing seems to help
Any ideas if I should worry about it?
 

 
Thanks!
João

 

[cruzzfish]

Change nutrients a bit and move the lights further.