Seedlings

Hi guys , this is my first time growing,i pretty much have everything right in my head except one thing I currently have 5 seedlings in a propagtor under a 150cfl , its only been 4 days since i opened the pack of seeds and now the plants have sprouted to atleast inch and a quarter already , so thats all good,question is when do you guys think would be the best time to remove them from the propagator and place them under my 400w hps dual spectrum (with fan blowing) , cheers

What are the seedlings in?? I sprout in jiffy pellets and move them to a bigger pot when roots start to show out the side of the pellets.