Im new to the game and have a couple of questions:

I have 2 cuttings under my 400 w lamp, on a 18hr on 6 off timer.
1 of my plants seems to be growing but the other isnt.
I know its only been 5 days but i would have thought they would have done the same amount of growth. Why is this?

Also whats the recommend distance from the plant to the lamp?