Could be that whoever you got the clones from hadn't started feeding yet? Or are you in soil? Looks like coco / perlite.
I used to make the mistake all the time, take clones and root them and forgetting to start feeding them nutes as soon as they have roots.
Just a thought.
Hey dude and dudettes,
Long time smoking growing regular family man here. Love my pot, Love growing my pot and I am here to learn as much as I can from everyone and possibly add some of my own value.
Cheers to you all!