first time grower

I Have decided my girls are not stretching now all fan leaves are remaining tight together... I lowered the like to 12” last Wednesday as well as potted in 4” pots as I was experiencing some yellowing of the first serrated leaves, by Friday the leaves on two plants were curling like tacos, Saturday morning I decided to raise the light back to 18” and angle the fan down at them some more. When I checked them on Sunday the leaves seem to have went back to normal however are slightly deformed now, growth is really starting to pick up