When do I move seedling to aeroponics unit?

I have 2 seeds germinating in rockwool in a humidity dome. They are just about to fully open. I know once they open I am supposed to remove the dome, but when do I put them in the aeroponics unit?

i did some looking around for you and i found this..looks like once they fully sprout..https://www.rollitup.org/aerogardeners/1614-aerogarden.html

Thanks Desr, all of the writeups I found for aero systems were done from clones so i wasnt sure about seedlings.