In my own opinion young plants do not require much wattage or lumens as they do in flower.
I would only be running that bulb at full whack if you had more plants in the tent and you needed better light coverage.
Id also only run it at full power if you were to use it during flowering along side a HPS as dual spectrum's are what a plants craves.
If you find the plants are stretching to much you could turn it on to full power or just move the plants closer to the light.
Hope this helps.