grow room size

[kal17117]

hi everyone,

i'm going to start to build my grow room soon, just wondering what size would be adequet for a 400 watt light to get maximum crop yields. any advice would be gratefull.

peace. kal..

[Highlander]

How about 'whatever size you want'

the smaller the floor space the more light intensity the bigger the yield.

I would go for a 3' x 3' myself.

i'm sure someone will come along and give you the 'lumens per sq' ft' jargon pretty soon. if not, look at some of the older threads on grow room building.

[MrBenn]

The standard line is a minimum of 50 W per square foot...so in theory you could have 8sqFt......personally I'd go slightly smaller than that.

There are other factors tho' , what yeild do you want? what style of grow are you planning?

[Highlander]

Nice work Mr Benn.

You said the minimum was 50W .

What's the maximum?

[TrichomeUK]

High there Highlander,

The minimum you want to be growing herb with is 35W/sq.ft. (check BOG's grows at OG.com if you think it's hard-going).

The maximum without CO2 would be 60-75W/sq.ft., but this varies according to strains, environment, etc.

Generally, an indica-dominant strain requires less light than sativas.

Indicas, on average flower happily under 40W/sq.ft., and sativa dom's 50-60W/sq.ft.

Remember, though, the more light = more heat, so bear that in mind.

Balancing heat/light is important.

All the best,

Trichome

[Highlander]

Trichome

I'm building a growroom 3'x4'x6.5'=43m3.

With regards to temp. do you reckon 680m3 extraction will be enough for a 600w (gonna buy or build an air cooled reflector drawing air from inside the cupboard)

I've even thought of a 1000m3 extractor on a 1000w lamp or will this make the grow unmanageable?

Planning on a SOG.

Could be upto 48 plants in there!!!

::

[Mono]

Alright Highlander....

Shit, where's all your :RoCkIn: smilies gone....?

I'm building a growroom 3'x4'x6.5'=43m3.

I'm sure your maths are a bit wrong here.......I'd say it's more like 4sqm...not 40....

I think you're getting a bit carried away with your venting plans too....

I'm a minimalist with venting...just enough...but even Trichome...(hurricane force vents) will probably find 1000m3 extractor too much for your space.....

...You'll be changing the air every 15 seconds or something, and unless your grow-tent is extra sturdy you're looking at negative atmospheric pressures....real risk of implosion boy.....

Suppose you can't really OVERdo venting, but this sounds close....

ono....x

[chip]

Hi all

Highlander, ive got 400 cu/f/hr drawing from my room, 240 from the air cooled hood, and 160 from another vent. Not exactly sure of the room size but it is something like 4' x 6' i suppose, similar to your new project. It Keeps things flowing nicely, with plenty of air exchange. I think mono is right, 680 would be overkill, so I'd save yourself a few pounds and get a smaller extractor.

You sound real keen, which is always a bonus. Good luck with it.

Chip

Oops, nearly forgot Kal, I'm with highlander on that 1, 3'x3' sounds good. Any bigger and in a way you start to loose light because not as much light is reflected back in by the sides. I used to put reflective boards up in my grow room so that more light would get reflected back on to the plants.

[TrichomeUK]

Hi there,

For the 600W, I'd downsize to the 420m3/hr extractor (6" Inline Centrifugal fans, we're talking about here)

and for the 1KW bulb, I'd go for the 680m3/hr

- although that would be with carbon filters attached, which slow the air flow. Without filters, you could go down 1 fan again.

Mono, when you say "you're looking at negative atmospheric pressures....real risk of implosion boy.....", I know that you're refering to quite high extraction rates, but the negative pressure can obviously be avoided by using the same sized intake fan.

All the best,

Trichome

[The Fly]

:o

Sorry for using this thread but M.A.T. read your PM board Please. tf.

::

[Highlander]

Thanx for the feedback guys,

Mono that figure i quoted was the actual flow rate; so sorry.

Trich. if i'm gonna get the 6" fan wouldn't you say it's worthwhile paying that extra £15 to get that extra suuuck.

M.a.t. Ive been told that i could just use holes for the intake. if i had for example two round holes at the sides of my cubby what size do you reckon they should be?

cubby vol.=2m3

fan=680m3 per hour

[JollyGoodSmoke]

hi highlander

i wouldn't put holes in the side of your cubby as this would probably lead to light pollution i'd go with the intake fan

all the best jgs

[Mono]

......

cubby vol.=2m3

fan=680m3 per hour

You the :fuck: man Highlander.....the only one.....

Mono....x

[TrichomeUK]

Hi Highlander,

I would get the 420m3/hr in your situation; the 680 is overkill and could damage the plants with its strong suction, especially young plants forming roots/..

As far as passive intakes go, I'd make a hole twice the size of the exhaust - i.e. 6" radius; use simple maths to calculate are, then cover the passive intakes with louvered vent grills available from DIY stores, with the diagonal slits pointing down, and spray them black if possible, to minimise light.

Of course, don't have the passive intakes near a bright area then - keep it free so air can go in (run fans 24/7), but will be heavily shaded to prevent light getting in.

I've used this method, with good results, although having an active intake the same power as the exhaust is better.

In addition to this, remember to use a 6" clip-on fan or two inside to circulate the air inside the grow area/or use a larger fan.

All the best and have a good one,

Trichome

[chip]

Highlander

You could build a simple set of baffles to cover the inteake hole. I've made mine from the box an lti fan came in. Its hard to describe how to make it, I'll tell you about it next i see you.

Chip