Quote Originally Posted by low_rdr
First, HPS is typically in the 2100-4100 temp color range, and your plant will react better to 6k+ which are metal halide, not HPS.

However, to answer your question, you can easily FLOWER 6 plants under a 250w HPS, but you can easily veg 12 plants under a 250 W Metal Halide, I'm currently vegging 12 under 69 watts And they're VERY bushy, what matters, is the distance from the light to the plants, with an open light, you need at least 18" and a fan blowing on them. If you have a cooltube, you can set it much closer.

The difference in 250w vs 400w is the amount of light you put off, which increases your target area size, so instead of 2.5x2.5 with a 250w, you'd have 4x4 with a 400w, but keep in mind, that's more for flowering, for vegging, again I would use a MH lamp, but I'd have that sucker about 4' above the canopy, covering easily an 6x6 area, with side lighting, I'd do a 8x8 with 400w for veg, but thats just me, I honestly PREFER to veg under CFL's just because of the cost factor in replacing the MH and HPS lights.

I can FLOWER 12 plants with a 600w HPS lamp, each in 5 gallon containers- That's doing rows of 4, but I could easily do 3 rows of 5 for 15 plants.
Thank you man

Yes the first part i know, i do have a 250w MH, puts a lot more heat than the 250w Hps.
I flower with a 400w hps in another room (3x3x6ft) next to the veg one(2x2x5ft) 4 plants each time :thumbsup:
Medicatetoday Reviewed by Medicatetoday on . Wattage Vegetative Stage Does watts are important in this phase? For example,if i have one 250w hps for veg,one plant under this light will grow more slow then if i have one 400w hps? and less bushy? ;) Rating: 5