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Spectra for CPs

Cindy

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Hi everyone,

Thanks to Butch, I'll probably be blind with neck and spine problems by 2016. :jester:

It is his fault he introduced this link to me...but then again I guess I cannot really blame him for getting hooked and be willing to struggle with the DIY spectrometer that may not work best with a Android Samsung Note 4. :nono:

So here are the links to what I have recorded so far (until I figure out how to embed the pics directly here). These are different sets of spectra that I put together for comparison just for the fun of it, although I may find some correlation later on between the lights I am using (sunlight, white leds and red/blue leds in different ratio).

SpectralWorkbench

http:///spectralworkbench.org/sets/embed2/2999

http://spectralworkbench.org/sets/embed2/2997

SpectralWorkbench

There is a clear plastic cover on the T5 HO light set which I thought may affect the recording...1313 is with the cover.
http://spectralworkbench.org/sets/embed2/2995
 
Cool stuff, Cindy! I was interested to see that natural sunlight contains more yellow-orange than red light. Not being one who thinks in terms of nanometers I found the chart on this page to be useful:Laser wavelength charts - Lexel Laser

The white LEDs you used actually seem to be pretty decent in terms of red and blue light, naturally containing lots of green to make things look natural.
 
Nice! When I played with it, it was pretty tough to get a nice narrow slit (to get good resolution). I then made it with a Cheerio box, and it worked better. I think that it was because the distance between the slit and the DVD becomes longer.
 
Very nice work Cindy!
:hi5:
 
<iframe width='100%' height='450px' style='border:none;' src='//spectralworkbench.org/spectrums/embed2/66526'></iframe>
Dusted mine off and took some measurements.
This is the from the LED my "pink" Cephalotus is growing under

Due to over saturation issues, I captured the spectra after being reflected off of white paper

but anyways, I used embed command in Spectral Workbench, then copy and pasted the code into Terraforums

hth's
Butch
 
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That's interesting, I wouldn't expect such a large spike in a green wavelength, nor one down near ultraviolet. I've only really looked at spectrographs for LEDs though.
 
Here are my latest sets after Butch helped me with the calibration of the T5 HO and CFL.

Set 1
SpectralWorkbench - Set 3044

The white LEDs (Panel and Tank HL) are currently used for Nepenthes, VFT, Drosera, Heliamphora, Cephalotus, Byblis and Utrics. So far, all the plants are doing well with these lights.

Set 2
SpectralWorkbench - Set 3042

Soon, the various genera of CPs wiil be placed under the following combinations of red/blue LEDs to see how they response.
6R1B
2B5R
6B1R
 
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Cindy,

Curious, are the panel and tank made by the same company?
Their spectra is very similar
 
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This is pretty interesting . Now I have a new project and just in time to test my new COB led lights my son and I just built with the help of Naoki! Cant wait to build one and test my new lights.
 
  • #10
Cindy,

Curious, are the panel and tank made by the same company?
Their spectra is very similar

Hi Butch, the panel and tank LEDs are from different companies. The wattage of the panel one is more higher though...I have to be about 2-3 the distance away from the panel in order to get the spectrum without overexposure.
 
  • #11
Spectral curve very similarly though, I'm guessing the panel has more emitters or different secondary optics?
 
  • #12
There are many articles on how blue or red light affects the growth of the plants and I am a total noob. The decision to try this is entirely due to the fun factor, and also because the high red, low blue ratio has given me some success with Nepenthes (see the N. kampotiana below grown only under red/blue leds).










Here are the preliminary results from the use of the red/blue leds (different ratios). A pure coincidence...I didn't buy the pots to match the lights. I bought them way earlier. :-))

Some stuff to bear in mind...
1. The plants are all in lowland conditions: high humidity and 30-33degC
2. The Cephalotus plants were newly imported and definitely suffered some setback.
3. The starting size for each genus was as similar as possible and the plants were all from the same original conditions e.g. Viking seedlings were growing together ever since they germinated.
4. The bulbs are dirt cheap. :blush:

Set-up in January


Lights are switched on during the day on a 14-hour cycle


I actually did not photograph the plants individually when I started the experiment..ppffttt... :headwall:

Plants in April - order from the top: blue, purple then orange pot (corresponds to most blue, mixture and most red light)




 
  • #13
So it looks like the balanced light is doing far better than the single colors judging by your pictures. The Neps don't seem to care much though.
 
  • #14
Off-hand it appears that the blue did the poorest, which is surprising to me.
 
  • #15
Are these 3 bulbs drawing the same amount of power?
I had a lot of variability while testing a few available bulbs, ranging from 3W to 17W for the best one (sold as 45W).
[MENTION=8617]bluemax[/MENTION] (from what I recall from my plant biology classes, a long time ago so I may be partially wrong)
Red should be the most important wavelength, that's where chlorophyll-a have its peak absorption (in visible, also one in near UV). Chlorophyll-b absorbs in blue (and also in orange-red).
Finally chloro-a is ~twice more abundant than chloro-b so in term of photosynthesis efficiency (often labeled as PAR) red should be higher.

k5sYlG2.jpg


That's also why in most grow light settings, especially for TC, is a mix of red:blue with a ration 4:1 to 6:1
 
  • #16
The bulbs are 7W each. 6B1R, 5R2B and 6B1R.
 
  • #17
emc2 - nicely explained. Thanks! But I LIKE blue better! Ha!

I am reminded that I really need to measure the wattage on the led 'bulbs' that I am using. Stated wattage seems to be wildly inaccurate from what I have heard.
 
  • #18
Wattage for LEDs isn't a terribly useful number unless you're looking to calculate power efficiency since the efficiency can vary quite a lot depending on which diodes are used. They should be providing light output values in lumens at the very least, though growlights would be better with a PAR value as well.
 
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