1 Week Old Babies. What is Best Light Distance for Hps

It's been so long I can't remember how close to keep hps light from the tips at this stage. I know I'm good with 1 to 2 ft in distance. Is it the same with young ones of this age? The light is about 2 1/2 feet from them now and they look as though they are starting to stretch.

How big is the light? that would be fine for a 400w but after the second set of leaves I would drop it to about 18" then to 10"

i have my 3 week old seedlings under a 400w HPS that is about 2 hand widths above them and 2 x 100mm computer fans blowing between the plants and lights. temp sits on 27 all day long

I'd go with a foot away. Thats where i start off at. As long as its not too hot at that distance of course. then i just let the plant get taller and shorten the distance between its top and the light. after a while you'll have to keep raising the light occasionally to keep the top in that as close as possible w/o burning them spot. if you can hold the back of your hand under the light at the height where the top canopies will be for 60 seconds or so and it doesnt get uncomfortbley hot then your good.

definately a foot away....