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 kyuzo
Stranger Than Fiction
Registered: 07/05/10
Posts: 981
Last seen: 12 years, 1 day
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Are you running 2x 600w, or some other configuration?
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kyuzo
Stranger Than Fiction
Registered: 07/05/10
Posts: 981
Last seen: 12 years, 1 day
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Do you mean LUX or FCs? If you have access to an SLR you can use that to measure your foot candles, and from there, if still needed, convert to lux
http://www.orchidgeeks.com/forum/newbie-questions/292-measuring-light-levels-with-an-slr-camera.html
http://www.unitconversion.org/illumination/foot-candles-to-lux-conversion.html
If you mean Lumens, as opposed to FC, what would be the benefit of measuring the former, compared to the later?
Quote:
maryanne3087 said:
How high are your lights hung over your canopy to put watt/sq ft in perspective? I've hung my lights high in the past not being fully aware of how quickly intensity diminishes and believe that was the only thing keeping my yields from being stellar. Hopefully with near gear and being able to drop the lights down low I'll be able to yield impressively this time around.
It would be really cool if there was more of a benchmark for the footprint of your bulb but most people don't have lumen meters to measure light intensity at the canopy level, myself included. Is PAR radiation similar to lumens in regard of how quickly they diminish when traveling a given distance?
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 Harry_Ba11sach
cannoisseur
Registered: 04/20/08
Posts: 11,753
Loc: Nepal 
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2x 600W indeed.
Quote:
maryanne3087 said:
How high are your lights hung over your canopy to put watt/sq ft in perspective? I've hung my lights high in the past not being fully aware of how quickly intensity diminishes and believe that was the only thing keeping my yields from being stellar. Hopefully with near gear and being able to drop the lights down low I'll be able to yield impressively this time around.
It would be really cool if there was more of a benchmark for the footprint of your bulb but most people don't have lumen meters to measure light intensity at the canopy level, myself included. Is PAR radiation similar to lumens in regard of how quickly they diminish when traveling a given distance?
I try to keep it 12-18" above the canopy, but really I just read the plants. If the leaves start getting twisted on top from heat or light stress then I back the lights off a bit.
PAR reacts in exactly the same way as lumens with regards to distance. PAR only refers to specific wavelengths of light and their activity on certain photosynthetic pigments, it has nothing to do with the intensity of the light.
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kyuzo
Stranger Than Fiction
Registered: 07/05/10
Posts: 981
Last seen: 12 years, 1 day
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I never worked with HIDs before: how hard is it to adjust everything when your running multiple lights like that, and have them all venting through the same system?
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maryanne3087
Stranger
Registered: 06/27/10
Posts: 1,111
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 Re: watts per sq-ft  [Re: kyuzo]
#457092 - 08/08/10 11:17 PM (14 years, 4 months ago) |
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Quote:
kyuzo said:
I never worked with HIDs before: how hard is it to adjust everything when your running multiple lights like that, and have them all venting through the same system?
How many lights are you talking? More lights = possibly more complicated cooling.
A friend of mine runs 9 lights and just invested in insulated ducting and and a large blower to cool all 9 lights. The lights are set up as 3 rows of 3 and there's bends on each side to connect the hoods. He's technically drawing less air than he should (by the book) but sees no problems. He only replaced his bulbs after a year and a half or longer also (mentioning as excessive heat can damage your bulbs) he's my go to guy for air cooling approval as he had a mishap some time ago running air cooled reflectors without air cooling them and he says the heat inside gets far too hot for the bulbs and they burn out prematurely. Up until recently I was thinking of doing the same thing until he reminded me of how he had to replace all of his bulbs.
I've got a ~500 cubic foot room set up (floor space is about 8x8' or 64 sq ft) with 4 x air cooled 600ws and 2 x vertical lights I will use for side lighting where I find most appropriate. I've run the room to test it's cooling ability without plants when temps were 78F and the room didn't get much hotter at all, never reached 85F which was what I was hoping for. This was also during the day and our nights are never that hot. The 4 hoods are cooled with a 8" Canfan HO and the room is cooled with a 8" can fan HO on a speedster controller.
I think the most painful part about ventilation is figuring out how to make your intake and how you're going to discreetly exhaust your air. Keeping hoods cool is fairly easy so long as you don't skimp on gear.
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kyuzo
Stranger Than Fiction
Registered: 07/05/10
Posts: 981
Last seen: 12 years, 1 day
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I'm honestly not sure why more growers don't use insulated ducting, being that at my local Lowe's the stuff only runs an extra 4 dollars for a 25 ft box.
But getting back to my original question, i was planning to run a single 1000w light in a 5x5 (will only probably be using 4x4 of it as actual grow space) space, but it seems that i might be better off kicking up the wattage and getting multiple lights. My issue though is that i have some serious mobility issues and don't want to set anything up where it's going to be a bitch to adjust the lights.
But after thinking about it for awhile, I'm probably just needlessly worrying
Anyway, what would you light a 5x5 with? I rather spend the money and guarantee that I won't be under lighting the area, as opposed to having to adjust things later on.
PS ventilation isn't really a concern. I'm using the area where I grow most of my draculas and highland neps. So the area is maintained at 70 degrees, and already has ventilation fans installed. So running vents directly to the already existing output wouldn't be much of a hassle, and it's already blended into the house with decorative metal work
Edited by kyuzo (08/09/10 12:03 AM)
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Harry_Ba11sach
cannoisseur
Registered: 04/20/08
Posts: 11,753
Loc: Nepal
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Re: watts per sq-ft [Re: kyuzo]
#457127 - 08/09/10 12:16 AM (14 years, 4 months ago) |
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you would be absolutely fine with 1000W watts there. The only reason I'm running 2x 600W is because I could only afford a single 600W at first, and then after my first grow I found a second one much cheaper on craigslist and I picked it up. If you choose to go 2x600W or 2x750W then I can help you figure out a very easy way to adjust both lights, even from a wheelchair if you absolutely must. 
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kyuzo
Stranger Than Fiction
Registered: 07/05/10
Posts: 981
Last seen: 12 years, 1 day
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How do you think the 2x600 would compare with the 1000w?
Originally i decided on the 1000w due to the fact that you get better light penetration, and the only obvious benefit for 2x600, besides the extra 200 watts, was the more even canopy. Something that I should be able to easily offset by just moving the plants around
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Harry_Ba11sach
cannoisseur
Registered: 04/20/08
Posts: 11,753
Loc: Nepal
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Re: watts per sq-ft [Re: kyuzo]
#457150 - 08/09/10 12:51 AM (14 years, 4 months ago) |
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I think the 1000W will give denser buds overall, and along a vertical gradient the density won't depreciate as quickly.
the 2x600W will give you more consistent quality over a horizontal gradient, meaning buds at the edges of your canopy will fill out better but lower buds will likely still be somewhat fluffy.
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kyuzo
Stranger Than Fiction
Registered: 07/05/10
Posts: 981
Last seen: 12 years, 1 day
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I was just rechecking some measurements and rethinking a few things, and might actually get more *total* usable space if i go with a 4x8 growing area instead. And with that, I could run 2 x 1000, and keep my average 10w above the 50w mark, as opposed to 10w below
Would a long space like that present any special concerns for ventilation?
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maryanne3087
Stranger
Registered: 06/27/10
Posts: 1,111
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Quote:
Harry_Ba11sach said:
I think the 1000W will give denser buds overall, and along a vertical gradient the density won't depreciate as quickly.
the 2x600W will give you more consistent quality over a horizontal gradient, meaning buds at the edges of your canopy will fill out better but lower buds will likely still be somewhat fluffy.
Regarding fluffy buds and the light you choose I think this is relative to plant size.
I've heard time and time again from friends and online. 600w = plants 3 ft and shorter, some say they shine with plants 2ft and shorter and 1000w = plants 4ft and taller. If you grow 5' plants and use a 600w you're definitely going to see a lot of fluff but if you grow 2' plants under a 600w and 4'+ plants under a 1000w I think the density will be comparable. 600w's seem to be best suited for a sea of green or productive grower and most people I see using 1000ws like to veg for a while because they can't be bothered to produce clones to fill in their canopy every 2months.
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grod31
Ranger
Registered: 12/23/09
Posts: 769
Last seen: 2 years, 10 months
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lots of info im glad the threads can help
anyone else want to share there watt per sqft?
i would like to hear from people that have just under 50 or completely inadequate lighting.
and how does 50 watts a sq ft differ from cfl to hid lighting
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kyuzo
Stranger Than Fiction
Registered: 07/05/10
Posts: 981
Last seen: 12 years, 1 day
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Re: watts per sq-ft [Re: grod31]
#457283 - 08/09/10 11:38 AM (14 years, 4 months ago) |
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Mary, are you saying that you think some wattage would be wasted, while using a 1000 watts for a short crop?
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kyuzo
Stranger Than Fiction
Registered: 07/05/10
Posts: 981
Last seen: 12 years, 1 day
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Re: watts per sq-ft [Re: grod31]
#457289 - 08/09/10 11:45 AM (14 years, 4 months ago) |
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"how does 50 watts a sq ft differ from cfl to hid lighting"
From my experiance with t-5 and t-12 lighting, I think the most obvious draw back would be penetration, especially considering how "full" most pot plants look.
In fact, I just measured the output from a 2 bulb, t-5, fixture and you drop from 3300 foot candles, right at the bulb, to 1800 just with in six inches of empty space.
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grod31
Ranger
Registered: 12/23/09
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Last seen: 2 years, 10 months
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Re: watts per sq-ft [Re: kyuzo]
#457979 - 08/10/10 08:27 PM (14 years, 4 months ago) |
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so my plant is about 3 square feet sitting regularly
but if i were to bungee the plant in a bundle it would be closer to 2 square feet.
since this would decrease my sqftage it would increase my watts per sqft.
would it be beneficial or would it just decrease my light penetration?
--------------------
DO NOT USE mushmagic.com- THEY LIE AND SELL DRUGS TO CHILDREN
--------------------------------------------------
Back the tape up. I need it again!
Let it roll! Just as high as the fucker can go!
And when it comes to that fantastic note
where the rabbit bites its own head off,
I want you to THROW THAT FUCKING
RADIO INTO THE TUB WITH ME!
Not me. It would blast you through
the wall stone dead in ten seconds and they'd make me explain.
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maryanne3087
Stranger
Registered: 06/27/10
Posts: 1,111
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Re: watts per sq-ft [Re: kyuzo]
#459049 - 08/12/10 07:57 PM (14 years, 4 months ago) |
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Quote:
kyuzo said:
Mary, are you saying that you think some wattage would be wasted, while using a 1000 watts for a short crop?
When using 1000w's and short plants IMO you want to get the light as close to the canopy as possible so that the light doesn't cover more than 4x4'.
If it's higher it may cover 5x5' or 6x6' or something similar depending on the shape of the reflector, filling in the area with plants would help maximize yield but then you're looking at far too low watt/sqft = fluff.
The only waste of using a 1000w is hanging it WAY too high, and the fact that they produce less lumens per watt used which can be made up by the penetration power.
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Data
That Guy
Registered: 08/12/08
Posts: 4,038
Loc: Southwestern US
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So does this 50W/sq.ft only apply to HID lighting?
Is there a different rule for CFL's?
I currently have a 2.5 x 2.5ft that I want to rig up for CFLs
thats 6.25 sq.ft.
which works out to 312.5 Watts if i use the 50W per sq.ft rule
which works out to 12 or 13 bulbs...at 100W equivalent, or around 1300 lumens per bulb i think, i dont have them with me but i can get a more accurate number in 2 days. its either 1300 lumens or 1700 a piece.
would this be viable for the tent i have?
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“The Universe is under no obligation to make sense to you” -NDT
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kyuzo
Stranger Than Fiction
Registered: 07/05/10
Posts: 981
Last seen: 12 years, 1 day
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Thanks for answering my question Mary. But one point I am confused on, why would the issue of distance be any different when growing short plants, as opposed to tall plants? Either way, wouldn't the same set-up run into heat and light intensity issues at the same distance from the plants, regardless if it was 12 inches tall, or 8 foot?
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maryanne3087
Stranger
Registered: 06/27/10
Posts: 1,111
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Re: watts per sq-ft [Re: Data]
#459343 - 08/13/10 10:36 AM (14 years, 4 months ago) |
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Quote:
agmotes165 said:
So does this 50W/sq.ft only apply to HID lighting?
Is there a different rule for CFL's?
I currently have a 2.5 x 2.5ft that I want to rig up for CFLs
thats 6.25 sq.ft.
which works out to 312.5 Watts if i use the 50W per sq.ft rule
which works out to 12 or 13 bulbs...at 100W equivalent, or around 1300 lumens per bulb i think, i dont have them with me but i can get a more accurate number in 2 days. its either 1300 lumens or 1700 a piece.
would this be viable for the tent i have?
Equivalency of cfls refers to the light produced vs incandescent bulbs. A 13w CFL produces the same lumens as a 60w incandescent or whatever it is I don't have a cfl handy for reference. A HID produces twice as many lumens per watts as a CFL this is why I don't use CFLS. Some people argue that you can achieve better yield per watt with CFLS because you can place them literally 1" or less from the plants without burning where HPS are put a foot or higher above the plants typically speaking. CFLS also diminish in output over x amount of distance than HPS which is another huge drawback.
If you decide on CFLS you would want to consider how many lumens per sq ft you want. I've heard everything from 5-10 000 lumens per sq ft. A user on icmag uses 100 actual watts per sq ft using cfls and claims to be rather successful his handle is Dr.GreenGenes I think.
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maryanne3087
Stranger
Registered: 06/27/10
Posts: 1,111
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Re: watts per sq-ft [Re: kyuzo]
#459347 - 08/13/10 10:42 AM (14 years, 4 months ago) |
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Quote:
kyuzo said:
Thanks for answering my question Mary. But one point I am confused on, why would the issue of distance be any different when growing short plants, as opposed to tall plants? Either way, wouldn't the same set-up run into heat and light intensity issues at the same distance from the plants, regardless if it was 12 inches tall, or 8 foot?
Naturally tall plants are taller (hehe) making there bottom branches harder for light to reach. This becomes an issue with 600w lights as they don't have the same penetration power (too much light output is diminished at a shorter distance compared to 1000s). If you're growing 4+' plants you most definitely want 1000w lights, the 50w per sq ft would apply only to the tops of the plants IMO. This is where most of the light is utilized. The penetration and light intensity problems would apply to the lower branches as distance from the bulb increases.
I hope this answers your question. You can find charts online that tell you the lumen output at whatever distance. An example would be initial output of a 1000w bulb being 140 000 lumens then at 4' it's dropped down to 4000 lumens. At 3' it's at 10% of the initial output I believe.
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