it also would really depend upon how big your space is.. An HPS would be okay. I suppose for vegging but 600w HPS bulb.. you would need it way high, probably about 4/5 ft ++ above your plants. which in turn your just wasting the light & bulb away & your plants would stretch like "catbuds" is saying. HPS bulbs arnt cheap

young seedlings & clones, like a more lower level light, they have to be sort of worked into it. depending on space size & growing conditions and how tall you want your plants to get.

the new trend now is CFL for vegging which is similar to T5's, which has been getting the same results as a MH but with less heat & cheaper bulbs.

so to answer your question.

400w MH bulb would be better for vegging from seed or clone,

however, a 400w MH could possible be too strong in the beginning. depending on space, growing condition & strain, and if your doing seeds or clones.


IMO, HPS & MH are a thing of the past, technology does advance