Strange plant curl

Don't quite know whats going on here, but the plants leaves are curling in a weird way. Got two of these under a 125w cfl and only one is curling in this way. I stopped using nutes about a week ago and have seen them grow rapidly!

Any advice would be awesome

you need to be more specific if you want an answer

Sorry - too stoned to remember the picture haha
Using soil and water with a good ph
Using 18/6 lighting and fan, temperature around 28C with the light on and high humidity of around 40%ish (minor changes at different times of the day)

when the leaf curls at the edges, that means it is a bit hot, move the light further away, but just an inch or two