i had my light on 24 at once. n dis sided to change to 18/6 and i knowest it will start to drop 2 hour before the light goes off and when is morning comes the leaf is up and has grown. i think when i wus doing 24 it wus busher and shorter. and 18/6 give it height but less leaf. that what i saw from what i did. just my 2 cent. :rasta: