When do Iturn on the lights?

[Opie]

I have two seedlings that are in rockwool. One is at the surface and the other has sprouted with two pre-leafs. I will get pics asap. I have a 4x23watt soft white cfl fixcture. When do I take the lid off my tray and turn the light on?

 

[FreakNature]

Since they've both broken the surface take off the lid and turn the lights on now. Imagine what it would be like in the natural environment.

 

[GanjaG]

The same time I put seeds in soil I turn on the light with timer that goes on and off in regular light cycles for my grow style. I figure in nature the sun is rise'n and set'n. I don't like the streach for light if they can't find it due to me not turning my lights on soon enough after they break dirt. A buddy of mine planted seeds and went away for 5 days. He came back to find 4 inch tall sprouts that fell over and died. He did not turn on the light hopeing he would be back in time, afriad to burn the house down while gone he left it off. What really is a few extra days of energy cost when you are about to run them for 12 to 20+ weeks dependent on strain and style of growing.