24hr Lights on cloner

I've heard more than once that a plants roots grow during the period they're not getting any light. I'm cloning for the first time, and I'm using a EZ-cloner type cloner and have them under florecents 24hrs. While they've shown vigorous foilage growth, not much has gone on for root growth since I started them 2 weeks ago. Does that sound normal? Should I have a period of darkness in that 24hr cycle?

pictures? naw u should be able to do it 24hrs light with no issues. Make sure roots are in complete darkeness, (dark bucket)