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Watts/lumens per square foot ?

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Watts/lumens per square foot ?

Texas Kid 279 Replies 97,453 Views
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Regarding light bleaching... Does anyone have a guess as to WHY tips of buds close to light get bleached. I am feeling this run that it is actually a lack of nutes making it to the tip, and not necessarily light or heat related. Thoughts on this?

FWIW, I blast a 4x4 with 1200w and let the plants get pretty close and have never had bleaching problems.

outwest
 
Regarding light bleaching... Does anyone have a guess as to WHY tips of buds close to light get bleached. I am feeling this run that it is actually a lack of nutes making it to the tip, and not necessarily light or heat related. Thoughts on this?

My best guess is that the plant can't get enough water and/or nutrients to the affected zone quickly enough to stave off damage. This may be due to poor plant vascular system or roots, or environmental issues like high temperatures or low humidity- or all of the above...

Squiggly has said that high light intensities can actually damage the very products of the photosynethic process, so perhaps there is some protective mechanism that also gets overwhelmed and leads to bleaching.
 
little tidbit from a retailer, might have to fix the url (greners)

There is no way this test is accurate. Maybe the Radiant is that high under the hot spot. And those Luxor hood are stupid, just stupid and huge. Im sure the adjust a wings are higher then that.
 
There is no way this test is accurate. Maybe the Radiant is that high under the hot spot. And those Luxor hood are stupid, just stupid and huge. Im sure the adjust a wings are higher then that.

The error in this test is equating peak light intensity across all the reflectors, without paying any attention at all to the overall spread pattern. Sure, the luxor has a great peak intensity, but that's not what I want out of my hoods, because I'm growing in a large area. Why would I want a really bright hotspot??
 
Ttystikk, did you see this?

Discussion

Measurements - Lumen readings were taken on a 5x5 grid covering a 4'x4' area, using a high quality Hanna instrument, and a decent meter from China. The lowest point of each setup was placed 24" above the surface - so for the vertical parabolic reflector the tip of the bulb was at 24", for the air cooled reflectors the bottom of the glass was at 24". The bulb used was a Hortilux Super HPS EN 1000W (broken in prior to testing), powered by a Lumatek 1000W Dimmable ballast. The ePerimeter value is the sum of the readings along the edge of the grid, the outer 16 spots. The eInside value is the sum of the readings in the center, the inside 9 spots.
Surprises - The Xtrasun Wing reflector did amazingly well and easily earned the best value award. Considering their advertising we were surprised how poorly the Adjust-A-Wing medium performed (the large is intended for an area greater than 4'x4' so no surprise there). It was pleasing to see that the Luxor did live up to the expectations from being engineered from the ground up to be the top performer.
Thoughts - On the accuracy of the data... the results are accurate and useable. We did two different types tests to get a margin of error and out of that testing we get an error span of 3.2%, with 2.3% being on the low side, and 0.9% on the high side. This test does not factor usability and features, it is just about efficiency - for example the XXXL is a much lighter and easier to use reflector than the Raptor, the Melonhead has great airflow, and the Luxor is slightly unwiedly.
 
Direct sunlight is 32,000-132,000 lux. Lux is equal to lumens per square meter. 3'x3' is equal to 0.8364 m^2. So the dual 600W gives 180,000 lumens/0.836 m^2 = 215,200 lux. The single 1000W HPS is 173,400 lux. Tex seems to aim for much higher luminosity than sunlight. The obvious difference with sunlight is the spectrum, evenness and penetration.

I've been flirting with the idea of T5 for a while. Four bulbs per linear foot gives 54W/sq.ft. An 864W, 16-bulb T5 covers a 4'x4' area (1.5 m^2). T5 put out ~5000 lumens per 4' bulb...which works out to 80,700 total lumens; 54,000 lux at 12", 108,000 lux at 8.5", 216,000 lux at 6" (for argument's sake). So it seems T5 are on par with super intense HPS - would Tex approve? Light distribution is also virtually equal across the entire area. You can also cut bulbs - to lower light intensity without changing the colour spectrum. T5 are replacing HID in industry - they deliver more light at a lower electrical cost, with higher lumen maintenance and lower bulb replacement cost.

I now think it's proper to use initial lumens instead of mean lumens...however, lumens drop ~10% after two crops (1600 hrs).
 
My deciding factor in choosing a t5 was seeing a friend of mine pulling down constant lb harvests with 8 bulbs....I can say I've never hit a pound with a 400 barely with a 600.
 
T5's and EFDL are replacing HID in industry. I predict that the price for HID lamps will fall dramatically as they try and keep market share. Of course growers will be the last ones to see those price cuts, at least at a retail level.

Take a look at the references page of this link and you'll see why the limiting characteristics of HID represent why large indoor and commercial greenhouse production growers look for solutions that meet and do not exceed DLI. And it doesn't hurt to have the fed give you a $1.80 per sq ft accelerated tax deduction on the retrofit coupled with the utility rebate to do so. The reference page gives you the links to that info and more

EFDL? What's that? What about DLI? Please use acronyms only after defining them.
 
Hey look, it's CHAZ! You're back, even after saying you were done because I called you and mother teresa fucking liars! Back to pimp some more INDAGRO shilliness!

Ttystikk, he's trying to convince you to buy a bunch of overpriced induction lamps they can't seem to move because guys like us want to see at least a few legit journals after over 4 years of bullshit on mostly other forums besides this one. (btw, he's talking about 'daily light integral')

Welcome back Chaz, gonna tell some more lies for us?
 
EFDL: Electrodeless Fluorescent Discharge Lamp

The report itself may not interest those not involved in large indoor or commercial greenhouse cultivation but the energy savings aspects as it relates to varying sunlight conditions control when attempting to dim HID systems is noteworthy. It also goes on to say that the HID lamps are prone to shortened lamp life and spectrum shifts when dimmed.

The NEMA link can be found on the references page.
 
Direct sunlight is 32,000-132,000 lux. Lux is equal to lumens per square meter. 3'x3' is equal to 0.8364 m^2. So the dual 600W gives 180,000 lumens/0.836 m^2 = 215,200 lux. The single 1000W HPS is 173,400 lux. Tex seems to aim for much higher luminosity than sunlight. The obvious difference with sunlight is the spectrum, evenness and penetration.

I've been flirting with the idea of T5 for a while. Four bulbs per linear foot gives 54W/sq.ft. An 864W, 16-bulb T5 covers a 4'x4' area (1.5 m^2). T5 put out ~5000 lumens per 4' bulb...which works out to 80,700 total lumens; 54,000 lux at 12", 108,000 lux at 8.5", 216,000 lux at 6" (for argument's sake). So it seems T5 are on par with super intense HPS - would Tex approve? Light distribution is also virtually equal across the entire area. You can also cut bulbs - to lower light intensity without changing the colour spectrum. T5 are replacing HID in industry - they deliver more light at a lower electrical cost, with higher lumen maintenance and lower bulb replacement cost.

I now think it's proper to use initial lumens instead of mean lumens...however, lumens drop ~10% after two crops (1600 hrs).


Your math is on point, but I can't say T5's are on par with super intense HPS lamps because from your own info a T5 at 6" is 216,000 lux and only 54,000 lux at 12". So when flowering plants its hard to keep all the buds within 12" of the bulb considering how big plants get during the bloom phase, even if you scrog the plant, the T5's have weaker penetration capabilities compared to HPS.

So for veg, T5's are great because you can easily keep the majority of the plants within the sweet spot (12" or so) and I wanna get me a nice T5 4' 8 bulb fixture, but when it comes to bloom I still have to say the HPS are more efficient and can penetrate the canopy relatively easy so you will get a bigger harvest so the extra money for electricity is off set because you will harvest more with HPS.

Don't get me wrong, people can flower with T5's and get good results, also, T5's are my 2nd choice behind HPS's for flowering, so I'm definately not hatin on them.
 
'The Vapor Room, which has been a Haight Street mainstay since 2004, is shutting down due to increased pressure from U.S. Attorney Melinda Haag, who cited the collective's proximity to the Duboce Park playground as the reason for her actions.'

http://www.huffingtonpost.com/2012/...g_n_1660582.html?utm_hp_ref=medical-marijuana

Duboce Park Playground...Complete and Utter Bullshit. The state gov't giveth and the fed taketh away. One last chance to visit them next weekend when I'm in SF for the show. Looks like the Feds are seizing D'Angelos Harborside property in a civil 'forfeiture' action too. Must be some kind of park near there as well. Truly a sad state of affairs. Initiatives mean nothing. The 10th amendment is nonexistent.

If you're drawing over 50Kw hrs/day on a residential service.... I suggest don't


......and this has what to do with watts/lumens per sq.ft.??????
 
Your joking......right??

Well, no. High power usage is something that cops can find just by asking the utilities; they have had a close working relationship for many years. They don't actually use this data in court because they know if they did, there would be an injunction against it so here's what they do instead; (true even in legal med. states like Colorado) they get the lists of high power users, then they go to the addresses and snoop around. When they find something, THAT'S what they use to get a warrant, and somehow the initial step of abusing our constitutional rights to privacy in our papers never comes to light.

If a grower tries to use too much power, for example, by increasing their light pressure on the same square footage, that definitely makes a difference. Hence the connection.

You best think before shooting from the fingertips with me, kid- it's pretty clear that you think you know a lot more than you actually do. Keep in mind the old saying, 'brain learns best when mouth is shut'
 
Well, no. High power usage is something that cops can find just by asking the utilities; they have had a close working relationship for many years. They don't actually use this data in court because they know if they did, there would be an injunction against it so here's what they do instead; (true even in legal med. states like Colorado) they get the lists of high power users, then they go to the addresses and snoop around. When they find something, THAT'S what they use to get a warrant, and somehow the initial step of abusing our constitutional rights to privacy in our papers never comes to light.

If a grower tries to use too much power, for example, by increasing their light pressure on the same square footage, that definitely makes a difference. Hence the connection.

You best think before shooting from the fingertips with me, kid- it's pretty clear that you think you know a lot more than you actually do. Keep in mind the old saying, 'brain learns best when mouth is shut'


WTF!!?! Why you acting like a troll?? calling me "kid" and "you think I know more then what I do" blah blah blah. I asked you a question, because I honestly didn't know if you were being sarcastic or not, hence the question marks (????).

I already know what the cops do with electric companies, so you didn't teach me anything. What chaz said has nothing to do with the topic of this thread, because we are talking about lights in the grow room, not how expensive your electric bill is.

Get a life and stop trying to start an argument that isn't there, you ain't got nothing better to do with your life except talk shit to a me (a fellow grower) on the internet, you must be so proud of yourself, old man.
 
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