I am on my first grow and only 2 weeks in but I started all of my seeds right in the rockwool right in the hydroton right under the light. All seeds germed within a week and were sticking up. Can you see down in the rockwool? You should be able to see your seedling in there and see what its doing. I always pulled the hole in the top open a LITTLE just so I could see what the seed was doing in there and if it was germing and if it was about to pop out because I had some that were way slower then others.