Leaves are curfling inward! HELP

I don't have any pics. I will keep this quick an easy. My plants are 4 weeks old and up until last weekened the leaves started curling inward. I havn't used any nutrients and there leaves are still %100 green. I have no idea what would cause this although yesterday I started giving the nutes and it hasn't done anything. Please help I need to cure these girls.

I apolgize, they are actually curling outward and not inward.

Maybe ur room temp is off or airflow clogged? Either need a pic or alot more info

room temp is 80 and himudit around 30% although I don't have any fans running. Will stale air do this?