Talk:Grow light

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"fluorescents are replacing metal halides due to their efficiency and economy."

Fluorescents rarely reach the efficiency of HID lamps. They are more economical, yes, but efficiency for CFLs and anything up to T8 fluorescent lighting pales in comparison to most HIDs, with your best T5 barely hitting 100 lumens per watt while HIDs can reach 130+ lumens per watt at equivalent color temperatures.

To the talk below re: LED spectral absorption - as an LED lighting researcher - almost every bit of info regarding LED grow lighting is dead wrong, right down to green light not being used for photosynthesis (why do you think HPS lights, with their heavy green output, work so well?) - see http://pcp.oxfordjournals.org/content/50/4/684.full most forums only perpetuate advertising nonsense and should never be used as a citable source.

"For the chlorophyll absorption peaks (chlorophyll a and b each two peaks each"

You totally ignored the UV range, which both chlorophylls have responsive peaks in. Tested and proven by John Lydon on medical cannabis back in 1987.

Oh, and as to Wikipedia is not a forum - do you ignore your own talk page? It certainly performs EVERY function of a forum.

71.95.53.61 (talk) 22:47, 30 July 2014 (UTC)LEDPunisher

I need a link to verify chlorophyll absorption peak and LEDs. The only one I can find is www.gurugrowlights.com/research.php but I already used a link from them to show a grow test. Anyone one got any suggestions? —Preceding unsigned comment added by Phlie (talk • contribs) 21:50, 13 November 2009 (UTC)

Wikipedia is not a forum

I just read the content in the "Wikipedia is not a forum" link, and the question above seems quite legit. Discussion of how to improve an article is acceptable on the talk page. —Preceding unsigned comment added by 140.242.210.2 (talk) 21:17, 10 January 2011 (UTC)

For the chlorophyll absorption peaks (chlorophyll a and b each two peaks each, and then there's carotenes and xanthopylls to consider), googling "photosynthesis spectrum" gets a bunch of promising-looking hits. I haven't checked them to see what's suitable for WP, but good enough for what I was looking for. For LEDs, no such luck so far. --50.133.131.206 (talk) 07:07, 25 November 2012 (UTC)

Orphaned references in Grow light
I check pages listed in Category:Pages with incorrect ref formatting to try to fix reference errors. One of the things I do is look for content for orphaned references in wikilinked articles. I have found content for some of Grow light's orphans, the problem is that I found more than one version. I can't determine which (if any) is correct for this article, so I am asking for a sentient editor to look it over and copy the correct ref content into this article.

Reference named "luminosity": From Incandescent light bulb: See luminosity function. From Luminous efficacy:  

I apologize if any of the above are effectively identical; I am just a simple computer program, so I can't determine whether minor differences are significant or not. AnomieBOT ⚡ 14:28, 14 March 2011 (UTC)

Green Light?
I just noticed that the Efficacy table lists green, 555nm light as having the "maximum possible luminous efficacy". It was my understanding, however, that this green light is (nearly) entirely reflected by leaves, hence their green colour. This would place 555nm light closer to the "minimum" efficacy, would it not? Mikeeg555 (talk) 21:11, 5 April 2011 (UTC)

Correct, Mikeeg, but if you look closely that table is actually talking about "luminous efficiency," meaning "lumens per watt." Lumens measure the responsiveness of the human eye to light, not the responsiveness of a plant. The real question is, "why is this section even in the article if it so clearly irrelevant to plants?" CmdrSunshine (talk) 03:35, 2 February 2012 (UTC)

And on the subject here's a light curve for plants. Notice that 555nm is, indeed, the minimum efficiency. http://hyperphysics.phy-astr.gsu.edu/hbase/biology/ligabs.html CmdrSunshine (talk) 03:38, 2 February 2012 (UTC)

Screw this, I'm adding a dispute tag to that section. If no one deals with it in a few weeks I might get around to fixing it, assuming I can find better data. CmdrSunshine (talk) 23:02, 11 July 2012 (UTC)

Do they not even teach the concept of entropy anymore?
"The bigger the plant gets the more light it requires; if there is not enough light, a plant will not grow, regardless of other conditions.[citation needed]" How exactly does this require a citation? It's not exactly 'original research' that without enough light, plants can't replace energy used by their cells. They'll eventually decay in the dark, for example.

Granted: It seems poorly stated in that quoted text. It doesn't state if it's relative or absolute magnitude that is being talked about. Clearly, a larger plant has more surface area and thus needs a higher wattage of light, assuming all other things equal. I'll leave it to an expert in biology to find an exact 'formula' to cite and update this text to be clearer. 75.70.89.124 (talk) 00:43, 24 June 2013 (UTC)


 * I think that is self evident. This article is related, and its less than a day old: http://phys.org/news/2013-06-sums-night.html. - Sidelight 12 Talk 03:38, 24 June 2013 (UTC)
 * I removed the template. but it may be put back. Either way an improvement has been made with a related insertions with a reference. This is obvious to anyone who has ever had a potted plant, but it may border original research. If this stays its because it is general knowledge, and not everything requires a reference, like the sun comes up everyday. - Sidelight 12 Talk 04:00, 24 June 2013 (UTC)
 * Well, my concern is the volume versus area problem in biology. An exact formula like the ones for combustion and respiration would be nice.  75.70.89.124 (talk) 06:13, 31 July 2013 (UTC)

LED grow lights ??
"However, 3 watt and even 5 watt LEDs are now commonly used in LED grow lights. LED grow lights are now being produced which exceed 1200 watts."

In talking about 1, 3 or 5 watt LED grow lights, you mean individual LEDs.

In talking about 1200 watt LED grow lights, you mean arrays of many LEDs.

Is this what is meant? C7nel (talk) 19:40, 24 August 2014 (UTC)

Reference 8
(It may not stay as 8 if other references are added.)

The reference I mean is http://pcp.oxfordjournals.org/content/50/4/684.full

The title is "Green Light Drives Leaf Photosynthesis More Efficiently than Red Light in Strong White Light". A confusing title I think. Is this intended to mean that a spectrum of wavelengths will be made more effective if some red in the spectrum is replaced by green?

This seems to directly contradict an early part of our article, which currently says: "Different stages of plant growth require different spectra. The initial vegetative stage requires a blue spectrum of light, whereas the later "flowering" stage is usually promoted with red–orange spectra." and DOES NOT MENTION green.

Can this discrepancy be resolved? Thanks C7nel (talk) 20:00, 24 August 2014 (UTC)

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"ballast"?
The word's used in the article without explanation. A quick search got me  which it probably is, but could someone verify and add a hyperlink for this term? Thanks 85.211.195.121 (talk) 21:38, 6 December 2018 (UTC)

Pink vs. purple grow lights
Since the red to blue ratio of grow lights can vary, they cannot be grouped under one color term. Those with a higher red to blue ratio will appear more pink, while those with a lower red to blue ratio will appear more purple. I put this information in the article to clarify the difference. ANDROS1337 TALK 21:18, 17 March 2022 (UTC)