Should I get a 1000W system?

I have been setting up a full hydro grow room for the past month or so. my first purchase was a 400w hps grow light. I now have the legal ability to flower 18 plants at a time and have 36 vegging. There are three medical patients working together on this. Anyways, The ebb and flow tray in my flowering room is 4' x 4'. I plan to have 18 plants flowering at a time. Will the 400 watt work very well? I have a friend that wants to start growing and said he will buy the 400 watt light for what I got it for. I just got an inline fan and carbon filter. I need to get the temps in my room down a little, so I was thinking of an air cooled hood. I have the cash for the upgrade, and at this point it'll only be an extra $150 or so to upgrade to an aircooled 1000w light which I can swing. How much will the 1000w light increase my yeild over the 400w in a 4' x 4' space? Btw I am planning on growing big bud and using botanicare nutes.

Im A Med Pat. As Well, Check The Gallery,,,,,i Run 1000w On Both Sides, My Op. Bigger Is Better, U Can See My 2/2 Eb Flow In Some Pic's It Is Off Set Because Light Was Greening My Clone Water I Off Set Her And Pull The Bigest Clones From It....check The Pic's Bigger Is Better...just My Thoughts. Dbb.

yeh definatly upgrade if you can,you wont regret it,,,,peace

yeah that's what I am thinking too. If I stick with the 400w system, I'd at least set up some flouro side lights. probably wouldn't make much of a difference though would it? Hmm, I guess I should buy the 1000w system, I don't think I'll regret it.

This is the system I am leaning towards. what do you guys think?

1000 watt HPS Grow Light 6" INLINE AIR COOLED REFLECTOR - eBay (item 180163635624 end time Mar-24-08 07:14:51 PDT)

Am I right in thinking the larger 20x24" reflector will work well over the 4' x 4' tray, or should I save $20 and get the regular air cooled reflector?

1000w Does Make Heat, Winter In Or. Its Ok, Sum. I Fight It Alittle Have Ac. Tho....check My Blm Room Pic's I Stab My 1000w Hps Into The Room, Not Reflected From Abv...i Get Better Ripening On Lower Brnches. And A Bigger Yeild Because Of This...the Lowers Get To Lookin Big And Like Toppers....just My Thoughts...dbb.

I live in California by the beach, so our temperatures are pretty moderate. I also have an ac set up in there just in case. how well do these air cooled hoods work? Do you think the 1000w system with an air cooled hood pulling around 320cfm will warm my grow room up much more than the 400w system without any more exhaust ventilation? The ballast will be outside the grow room, so it shouldn't effect the temp at all.

Time To Bust The Tape Out,,, Im Getting A Blower This Summer To Help My Self As Well. So I Really Cant Answer That Quest. Most 1000w Sys. Ive Seen Tho Are Being Exhausted...i Am Want To My Self...easier To Make Heat The Cool....dbb. Just Turn Of Exhaust....im In Or. Just Up From U In Protland.

Boy I Chopped The Spelling In That One......mesure Ur Rooms To Get Callc. 4 Sizeing....of System Needs....and Start Reading Boxes And Performce Charts... Just My Advice....dbb.

well, the volume of the whole grow room that the fan needs clear is approx. 500ft^3