what to do after first sprout?

[Iceberg420]

Hello everybody, I'm a noob trtying to get in that first grow, I started germinating 6 seeds in rockwool 2 days ago and one has sprouted.... do I leave them in the dark until the rest sprout or do I turn on the flourescents that it's under?? I', totally clueless of weather keeping them in the dark or turning on the two t8 flourescent fixtures that stand s above them??

put the ones that sprout under the light lol... or else they'll stretch and die... or die and stretch