BlazedMonkey

Well like i said for that weight you probably need HPS, however from my reviewing journals and such i would suggest either
Pro Grow by Hydroponicshut
GrowLedHydro
^ Top two
Heard advanced LED was decent but might want to do a bit more fact finding on it
Also heard some good reviews about Blackstar (although some people say they are made cheaply) (also cheapest LEDs for the W usually so probably why lol)

Find irishboy though if you want an LED hes reviewed a bunch and he has multiple threads on multiple forums seems to know a good deal about them.

I feel yah:/ i poured over grows looking for the right light, before i decided LED i was going to get a 150 then heard 250 wasnt much more heat and more lumens then people said might as well go 400. Magnetic, digital yada yada yada. It bogs you down.

Id be happy to try to help you with any questions however let me say that i have ZERO experience growing to the scale you wish to grow and have not even really read alot on those kind of grows. Now if you can grow 4 plants id imagine the learning curve for 40 isnt as hard as the first 4.

Like i said though never ran an HPS, Go to the harvest and cure section and look for a thread saying "huge yields in closet" or something to that effect he got crazy amazing yields from a 400HPS and would be able to help you more in that regard.

http://www.rollitup.org/harvesting-curing/278158-massive-harvest-small-closet.html
found it

That or sort grow journals by views and start reviewing and asking politely members, specific questions.

and put.... some say 4 plants under each lamp and some say give each plant a square foot.... that means 16 plants under each lamp! it is then said that each plant should give up to 125grams. you begin to see my problem? i hope.
so if you only had 4 plants do they then produce way more than 125g each. please, any advice that you can give me on floor area per plant, plant names, plant yield and LED units in the uk, if you know any that is, would be so welcome.
i will get this sorted. thanks for your time and help.
querty.

hi there. this message is too long............found that out after typing it so i will post as two parts. i need 50 posts to send you private mail.
I am sooo confused. the more i read the worse it gets! so here is the situation. my grow room is 15 feet long and 7 feet wide and 7.5 feet tall. it looks like 4 kg is too expectant. so i am now looking at a grow of 3kg. as you know i have to pay attention to the light working "foot-print". it seems that a lot of this indusrty is based around the 4 feet x 4 feet grow area and multiples of that. i also know that i need to be able to get around my plants to look after them and also need a lot of space in the room for all the other equipment. because of that i have put over 2 squares within the room of 4 feet x 4 feet each alowing me access to 3 sides of each square. now with non LED lights it looks like i would use a 600w lamp for each of these squares

hows it going

cleaned it up ask away...