How big of an HPS light do i need?

right now i have 20 seedlings under some CFL's... i would like to veg and flower using HPS.. my grow room is 3.5'x4'x6' and i plan to keep only the best 1-2 fems from each strain... i'm wondering if a 250W light is large enough or if i should bump up to 400W? also, how far from the canopy does a HPS light have to be to prevent burning?

chromer.... BIGGER is better

1000 watt HPS....

start with it about 30 inches from your plants... with an ocillating fan pointed at a slight angle upwards towards your light... blowing the air/area inbetween your light and your plants... also get an exhaust fan that pulls the hot air from your light OUT of the ROOM/CLOSET... this is VITAL for small grow areas..

lower the light 1-4 inches everyday... put your hand at the same level as the TALLEST foilage... if your hand can withstand the heat, so can your plants.. this is called "the hand test"....

check your light/foliage relationship daily... plants grow fast... set the light up so that it is easy to adjust.. have a back up string/chain to catch the light in case it ever falls!!! many many new growers neglect this and drop the light on their plants.. I have been that dumb ass before LOL this is common...

the light will need to be adjusted frequently until the third week of flowering when the VERTICAL growth of the plants stops..

and NOW you KNOWM