if you are rooting in straight potting soil i suggest using small plastic cups so the roots are easier to see. then you'll know better when to put them under the big lights. i use jiffy cubes set inside paper 'dixie cups' and when the roots grow thru the cube i know it's ready for potting and under the lights. it usually takes 2 weeks or so for mine to be fully rooted and ready for an upgrade. i also wouldn't flower a clone until it's well established in its new home...but that's me.