my clones took a while to start growing after they rooted (roots out about 1 cm radius from stem) They probaly still have too much vegitation for the root system.

some more numbers would be great. How long since they've been rooted
how do you know there rooted.
did you give them any hormones
pics would be great.

Once they root they need lots of light. but i sounds like they got it. make sure all your variables are in check. Temp, light, humidity, watering. and consider giving them some nutes. very light at first. But then again they are in good soil. I always root in perlite sand a moss. so they need the nutes yours probaly dont

give it a week then start to worry