seedling question

when i have a seedling push thru the soil how soon should i get light on it and how far should i keep the light from it....it is a 400 hps mh conversion

I put mine under lights almost immediately. But I don't suppose its critical until the secondary leaves start to sprout.

put the light on it right away but start far away and gradually lower the seedling has to get used to it. you put it as close as you can without burning it.

Immediately and i would use low lite flourescents with a diffuser on the bulbs at first.You can have the flourescent close and u dont have to worry about burning the tender leaves. Also keep them under a humidity dome until the first leaves form completely. using hydro i keep them there til the roots hit the water then transfer them to the HID lites. you know when the roots hit because they start growing fast. No nutes just plain dh20 at first. after a week u can move the nute ppm to about 50 and make sure ur ph is in balance.