Help with starting seeds

[Drklude]

This is my first leap into the world of hydroponics. I'm going to be running an indoor ebb and flow system that I have set up and ready to go. I got a 24 pack of the rockwool cubes with the little holes in the top to start some seeds. The cubes are rough 1.5 sq. in. I soaked the cubes in water that I got to the proper PH then mixed in a tiny bit of the nutrient solution. I then placed one seed per cube, a mix of romaine and bibb lettuce, basil, parsley, and spinach.

I then placed the cubes in a jiffy grow tray with the clear plastic lid for the whole greenhouse effect, and then placed it next to a window. All of the lettuce sprouted within a few days. I let two weeks go by and still nothing but lettuce. I took the tray outside to give it more sun, but, I live in FL, and the result of being outside in the direct sun for a couple of hours was all my lettuce being fried.

Is there something I'm doing wrong that none of the other seeds sprouted? Should I just wait longer? I pulled the seeds out of the cubes to start over, and none of them had even started to sprout.

Any help or insight would be greatly appreciated!!!

Thanks.