DieLawn: There can be a lot of things affecting the germination and growth of our seeds in an Aerogarden. The age of the seeds and how they were stored can have a lot to do with it. Also you have to consider how well developed they were before harvest. If they're bag seeds it can be anyone's guess. If you got eight to sprout in an Aerogarden you really have nothing to complain about. My question is where are you going to put them? I hope you have a second A/G handy. I gave up trying to grow more than two plants in an A/G unless they're a really really small variety and then I limit them to three.
Once they sprout some will develop faster than others just like kids do. I wouldn't panic at this point. I've found that the ones in the center will grow faster and straighter to the light than those in the outlying holes so I'd be curious as to where your slow pokes are located. Don't stress, just enjoy it. You obviously have a green thumb. Please document your grow in a log and keep us posted.