are they OK?

http://farm9.staticflickr.com/8117/9...a18567d6_b.jpg

2 week after planting, they're roots are starting to grow but it seemed that they had problem sticking they're roots inside the rockwool cube. I'm not sure now.
they're were fed 6 times a day, now I lowerd to 3. they're on 18/6 hours light.


What's the green stuff on the rockwool? Is that suppose to be there?

Thanks for all the help,
Rob