lighting question

[Remedy]

K so I'm new to the forum but have been lingering for quite some time, also lingered on OG back in the day which honestly is what started it for me but on to my question.

I've been reading quite a bit and I'm about ready to set up a wardrobe (possibly double) grow. Thing is, I I'm a little confused on lighting. Do I use LxW Sq. Ft. or do I use LxWxH Cubic Ft? Do I use Lumens or Wattage per sq ft? is it 5,000 lumens/50 watts per sq ft the sun puts out at the equator or 10,000 lumens/100 watts per sq ft?

I've seen multiple things posted on multiple sites and with something like nutes thats ok it's opinion but this is what it is. its math. basically, I just want the correct ways to measure my area and proper way to measure the light I'd need for optimal growth.

also trying to figure out proper ventalation and a light trap for it but I can get more into that when I post a pic of my wardrobe(s). At the momment the wardrobe I have is about 2Wx2Lx4H and I'm thinking CFL though would love a lower wattage HPS but am worried about heat and possible distnace from plants (also plan on doing 12/12 straight through to reduce size a bit). I was thinking of buying a larger wardrobe soon thats about 4Wx1.5Lx6H and was def. going with a HPS in there with possible CFL supplementation, however, I have no idea what to go by.

any help here would be great. I've literally not been able to sleep well because I constantly think of the designs for these grows and the fact I finally can do a legit grow now that I'm out on my own...guess I just wanna get this puppy rollin'!

 

[MobbDeep]

post a pic of your wardrobe..

 

[midwestganja]

2Wx2Lx4H - 16 cubic ft, 4 sqft, gonna need a fan that will push around 50CFM minimum, lighting: i use 60-70w per sqft, some use more, some use less. at my calculations i'd run about 250w of lighting, and a fan probably 100CFM or so, though you could probably get away with a smaller fan.

4Wx1.5Lx6H - 36 cubic ft, 6 sqft, gonna need a fan that will push 100CFM minimum, lighting: again 60-70w per sqft is what I go with, but you could do less, in this space i'd pry go with a 400w, or a 600w if you could keep it cool.

The rule of thumb is 50w per sqft, the more the better, some people even go up to 100w per sqft for maximum light penetration.

The rule of thumb for ventilation is calculate your cubic feet of your grow space, and times that by 3. So 36 Cubic feet * 3 = 108CFM required to change the air 3x per minute. You can go less than that though also..

Might not be a bad idea to just rig up (6) 42W CFL's for your 2Wx2Lx4H area, that'd give you 252w and 63w per square foot, and a cheap 50cfm fan to cool and exchange air, done deal, cheap and efficient.


Hope that helps, a little bit.

peace

 

[Remedy]

Yeah, a lot! thanks for kinda clearin that up midwest. probably change wattage a bit but it all varies, just needed somethin to go off. i appreciate it though

Mobb, uploaded a pic of my current wardrobe. planning on changing the backboard out of it because its a paper thin POS, and then cuttin some holes for fans but im not exactly sure on where/how I'm going to do that yet. also might cut some holes for pots inside so that they rest in the lower drawer there leaving more room for growth.

 

[MobbDeep]

youre def gonna want some cfls in there..

 

[Remedy]

yeah, i was starting off with something simple but then i started looking into HPS and now I really wanna get the other wardrobe but I think what im gonna do is set this one up n do a grow, then hand it down to a friend of mine who is starting and then get the 6 ftr. kinda bummed but it'll still work fine

 

[Observer Tom]

If you're new to this keep it simple, the second version will be far better no matter how much you pre-think this one out. Hindsight is waaaay better than 20/20, if you can recoup your costs by passing the first version off to a friend then you'll be better off on the second version! =)

Plus, simple has a better chance of succeeding and if you're new there will be so many things that COULD trip you up, you'll already have plenty to watch out for.

 

[Remedy]

thats becoming abundantly clear as time moves on. i know a bit about most everything but i still lack the experience needed. anyway, im gonna go somewhere in the 250-350 watt range i decided and im tryin to decide now if i should just get a couple larger wattage bulbs like some 105's or if i should go with a couple small ones for even light distribution and how exactly im going to wires these up to plug into a single outlet..

but yeah def gonna keep her simple this time round.

 

[The Southpaw]

my advice is to not underestimate the smell the last few weeks... I have 2 girls in the besement at 8 weeks into flower and the smell is unbelievable and powerful! ( I like it ) and I have an ozone gen on a timer running..
Peace!

 

[Remedy]

right so i just spent the past hour or more at wal-mart and am thoroughly convinced they are now marketing to growers. the cfl's are next to the fans which are adjacent to the replacement air filters, RH/Temp gauges, adhesive foam sealant for air/light leaks, timers, power cords, zip ties, wire connectors, electrical tape, oh..and did i mention that this is all within 3 rows in the back of the store about 15 ft from the garden center?

anyway..picked up some stuff for the wardrobe and drying trunk that is also under construction and i had a ventilation question...i picked up a small personal 4" fan that i think will do well in the trunk (cfm isnt as large of a concern, i think the fan will do fine considering the size of the trunk) but the wardrobe still has me kinda stumped..i dont know if i could maybe use a bathroom fan.. semi-quiet, decent size duct, right cfm, inexpensive...but i'm not sure if it is practical size wise.

i was looking at these: http://www.homedepot.com/webapp/wcs...85001&storeId=10051&catalogId=10053&langId=-1


if anyone has an opinion on ventilation let me know, kinda in the dark on what to use.

edit: scratch that HID HUT has saved the day..4" 100 cfm fan for $10. i was thinking entirely too deep
sorry if i wasted space

 

[FreezerBoy]

Wattage is determined by square feet. Lumens measures the human eyes ability to see green light, the type of light the plant rejects (that's why it's green) forget lumens and go for spectrum. Even more important than wattage, all the light in the world is useless if it's the wrong color.

Fan ducts are easy. Get a hole saw the size of your fan and punch 3 holes in the cab. One at the top for fan and filter, two passive intakes at the bottom. Start planning your filter now. My recent 8 mile started stinking at 2 weeks before I saw a single flower.

 

[Remedy]

damn. well i have a couple filters in mind. one is a replacement cartridge for a paint mask, another is a replacement filter for an air purifier. as for the lights i was already lookin at that. iv got a 68 watt cfl that they said is a "warm white" because if i remember correctly they dont give ya numbers..or i could be mistaken because i know i was looking at some 2700k's. ill double check before i get them though. figured id put in four of those which puts me at 272 watts/68 wats a ft.

now freezer, you say to use the fan as the exhaust with a filter over it and then let the back pressure created bring in new air from holes at the bottom? do you think a 100cfm fan will pull through the filter alright? or should i go 250

 

[FreezerBoy]

I should've used the word scrubber or carbon filter. Whether 100 cfm is enough depends on the size of your cab and scrubber. My S&P can barely handle a 1" thick scrubber so I'm going to try one at 1/2 inch thick. Muffler DIY by Kovenant

Back pressure is to be avoided as much as possible especially with fans as weak as those above (post#10). You want airflow. The air flowing through the cab is where negative (low) pressure comes from. Air moves from positive to negative. It's why planes fly and baseballs curve. Now all air in the vicinity goes into the cab. The only way out is through the scrubber.

Back pressure can be used in muffling sound but, the fans you list in post 10 are weak (50 cfm) and incredibly loud (anything over 2 sones will need serious muffling. Over 3 means screaming loud) The more you muffle, the less air flow, the less cooling, the less scrubbing. At 150 watts or less, you may be able to make do with an axial fan and Odorsock type scrubber. I did. At 250 I needed a proper fan and scrubber.

Great Inline Fans (S&P) Ventilation 101

For multi lamps, you'll want to wire in "parallel."

 

[Remedy]

thanks freeze! very helpful, though sadly my grow has been put on hold due to reasons beyond my control. although i am putting together a tutorial of sorts for myself, once i can get this back underway ill have that file ready as a refresher crash course of sorts which ill def need with the ventilation info!

 

[Aerohead]

Depends on your budget? that cab could easily handle a 400w HID with a 6" Vortec style fan.

I would love to see one of these T5 fixtures in a cab like yours It measures 36"X17.5"X2" uses 8 X 39watt T5HO bulbs 312 watts, claims 32,000 lumens! Priced at 259.99 with 8 bulbs it's tempting...

 

[FreezerBoy]

t i am putting together a tutorial of sorts for myself,

Save it and post it! Especially any screw ups. My best contributions have been in the "hey, look what blew up in my face" variety.