leaves have blotches and some are curling. crit kush

[_Cannabal]

Yesterday, the leaves were pointng up, today they are curling a little. Could this be because the light only just turned on or should they not curl at all? I also found some blotches that appear to be a calmag deficiency but i changed out my water yesterday. The stems appear a bit purple but thats been something i could never get rid of, is critical kush known for being slightly purple? Heres some pics.

 

[TripsRabbit]

Looks like calcium defiency, you should try some garden gypsum.