LED Color Aesthetics: The Emperor's got no clothes. Or does he?

Crit21 said:
Wow, I didn't expect the Spanish Inquisition, LOL.

I posted privately because some people don't like non-sponsor links posted here. You asked for the information and I gave it -- privately. I can't support an arbitrary assertion that they're all scammers and crooks.

I got one set of Crees from the big US supplier, but the price was still too high, so I looked around and found the supplier I mentioned to you via the aliexpress site. I took a gamble and built my entire system with Bridgelux LEDs from that one supplier. I got a great price and great communication from the seller, they work perfectly, my corals look great, and they're growing like crazy, and from a professional electronics engineering perspective, I can see they're of sufficient quality to do the job.

I'd be interested in knowing what personal or professional experience you have had with the seller I bought from. My one and only experience has been a 10 out of 10. The technical and sales support were outstanding (actual live chat!). The products were as advertised, and they were at my door 3 days after shipping. I would recommend that seller to anyone without hesitation.
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Sorry, didn't mean to rock on you personally or even your one contact but recommending a site that is full of scammers in private and saying to contact a particular person is typically how most scams start. I don't think RC has an issue recommending a seller on that site. People recommend eBay sellers all the time. People just need to take a lot of caution dealing with aliexpres. More so then craigslist.
 
Crit21 said:
I wish I'd checked up on my "critic" before responding. He's even got Beerguy peeved: http://www.reefcentral.com/forums/showthread.php?t=1962189
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That is funny that you would link to that thread in this thread since everything I am stating in the thread you linked to is exactly what the people in this thread are looking to solve.

Personally, I think this is one of the best threads on RC as people are recognizing the issues with LEDs over a reef tank and trying to solve it. Unfortunately, I don't think it is the people in this thread that are going to solve the issue, but the producers of LEDs. At least people are trying with the available resources and hopefully some manufacturers are listening to provide better products to support the needs of the customers.
 
Balanced spectral composition and intensity. I have dug through a large volume of LED threads and there is painfully little spectral analysis data. My concern is that a large number of commercially available "Reef" LED fixtures are not properly balanced and despite high PAR output are overblued or lacking in other wavelengths leading to photo-inhibition, bleaching, or generally less healthy corals.

The most impressive results I have seen are from DIY LED fixtures and I would like to see how close to a true balance they are, or at least where the spectral peaks occur. The more peaks at the right intensity = more photosynthetic pigments activated = (hopefully) increased growth.
 
Thank you Acro. That is exactly what I was looking for and am interested in replicating. I am glad you included some red wavelength heavy LEDs to balance the spectrum.

Where did you get your spectral graphs?
 
JoeCreature said:
Balanced spectral composition and intensity. I have dug through a large volume of LED threads and there is painfully little spectral analysis data. My concern is that a large number of commercially available "Reef" LED fixtures are not properly balanced and despite high PAR output are overblued or lacking in other wavelengths leading to photo-inhibition, bleaching, or generally less healthy corals.
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That's not really accurate. The manufacturers publish specs for the LED emitters that include spectral plots. The vast majority of fixtures (whether commercial or DIY) use some combination of Blue, Royal Blue, Cool White and Neutral White (less commonly Warm White). You can easily find these plots.

Early in this thread an elsewhere we offered up research papers regarding spectral needs of various coral. Alternatively, you can find a spectral plot of a MH lamp that is known to grow nice coral (there is a wide selectrion of these) and look at the spectral plots of those. In the end, what you'll find is that we're realtively close. We could use a bump in the 420nm area (be nice, not critical) and a bit more in the cyan area (just above the blues) and also a bump in the far red (680nm more-or-less). But all-in-all the commonly used LED combinations (with the apporpriate optics) are doing a decent job.
 
jtma508 said:
and also a bump in the far red (680nm more-or-less).
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I'm not sure why you're recommending that wavelength region. According to the article you cited, red pigments fluoresce when excited by wavelengths from 486-589nm. Emissions are 506-620nm.

Regardless, don't forget the correlation between red light and photoinhibition: http://www.advancedaquarist.com/issues/nov2003/feature.htm, and the correlation between the amount of red wavelengths in MH bulbs and SPS growth rates (Figs 2 and 5 here): http://www.advancedaquarist.com/2008/12/aafeature1

I suggest that supplementing with red wavelengths has the potential for more negative effects (i.e., slower growth and possibly increased algae growth) than positive (fluorescence).
 
People are tanking the data in those articles WAY to far. Article 1 shows that a pure narrow band of red light produces coral bleaching. Adding some supplemental red light for aesthetics is not the same as seeing if a coral can be maintained under red light. The article also goes into many conclusions of the results, none of which are supplemental red light inhibits growth/health. One conclusion points to needing a wider spectrum of red light as research has shown that 2 light cycles occur in the red spectrum and both are required. The conclusion also state that red in a full spectrum bulb shows no negative effect on fungia.

Article 2 only goes to show that 20k lights generally have more PUR then 10k lights and references the other experiments on red light that that people are interpreting wrong.

Neither of these studies address a small or supplemental amount of red light. People need to watch what conclusions they come to from these studies. You may think of a hypothesis, but until you test that hypothesis, it is not TRUE! The fact that hundreds of successful tanks have pink fuji bulbs over them would provide stronger evidence that supplemental red light is not damaging to corals.

If you are going to site research to back up a point you are trying to make, please understand the research you are citing and generally the scientific method/logic.
 
Forgive me for believing the words of a well-educated, peer-reviewed researcher of corals and light making reasonable conclusions over people with no scientific experience, no established credibility whatsoever, and who offer no evidence to the contrary other than "they didn't die, so it must be good".

You mention unsupported assumptions, but as far as the extra red wavelengths in the bulb mentioned, no data is given supporting the assumption that growth rates under that bulb are no different than bulbs without the enhanced red.

I'll take scientifically-supported evidence over the "they didn't die" argument any day.
 
"Effects of Narrow Bandwidth Light Sources on Coral Host and Zooxanthellae Pigments"

You can't compare the results of hitting a coral with just one bandwidth of light to have that same band of light in your overall lighting scheme. Try raising coral under nothing but UV light. Doesn't work so well but a small about of UV makes them look pretty.
 
Crit21 said:
You mention unsupported assumptions, but as far as the extra red wavelengths in the bulb mentioned, no data is given supporting the assumption that growth rates under that bulb are no different than bulbs without the enhanced red.
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As far as I know, supplement of red color isn't really suppose to enhance coral growth, the red color is there simply to improve the LED color aesthetics, because the human eye react to red color better than blue.

I've been using red LED bulbs in my tank for well over 8 months and my coral didn't die, and have shown significant growth, but probably have nothing to do with the red color either.

Some people may not like the red/purple tint, but I do find it more pleasing to watch with the small amount of red color added.
 
The Grim Reefer said:
"Effects of Narrow Bandwidth Light Sources on Coral Host and Zooxanthellae Pigments"

You can't compare the results of hitting a coral with just one bandwidth of light to have that same band of light in your overall lighting scheme. Try raising coral under nothing but UV light. Doesn't work so well but a small about of UV makes them look pretty.
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I can imagine strong UV could cause a lot of tissue damage, which is why we use UV to sterilize tank water. I've also read that coral pigments may actually be a defense against UV.

I partially agree with your first statement, but it was interesting that the other wavelengths (blue and green) actually promoted growth, while red bleached them. Red wavelengths are definitely beneficial to photosynthesis in green plants (e.g., algae and terrestrial plants), but it appears they are not good for corals living in a low-red, high blue environment.

The second article actually gives very strong evidence that red light is connected to slower coral growth, as suggested by the fact that the bulbs with both higher and lower Kelvin ratings produced significantly more growth than the 10,000K bulb with the highest red spectrum emission. These were all "full spectrum" bulbs, so I wouldn't think it's a stretch to say that supplementing with red, while good for aesthetic reasons, may not be the greatest thing for overall coral health and growth.

I'm using cool white Cree and Bridgelux LEDs, as well as blue and royal blues. My corals are definitely growing faster under those LEDs than they were with 400W XM 14,000Ks and actinic VHOs, and the colors are better by the day.

Anyway, it's obvious that people have strongly held opinions on the subject. Go with what you like as long as you're happy, right?
 
Acrotrdco, I never got the impression that people were supplementing with red for growth either. I was just pointing out that there's evidence that red supplementation, while providing visual enhancement, may come at a price, that being slower growth.
 
i kinda skimmed through this thread, so sorry if i missed something important...

I guess i jumped on the bandwagon for my LED lit 5g, but going from T5 and PC bulbs, i prefer the LEDs. I have never had metal halides, but i would have to say i prefer the colors created by my 1:1 boring old nothing special LEDs over the others.

I have been asked about other colors of LEDs, and im curious if anyone who says they did not like their LEDs tried the red LEDs to compensate? How did their opinion change?

Again, sorry if i missed that somewhere in the thread
 
I just got an email from Dana Riddle. I had asked what new information was available beyond the two articles cited here. He had a lot to say, but these statements stood out:

"I can say with a high degree of certainty that red wavelengths are detrimental to zooxanthellae pigment content and health."

"Dr. Kinzie published his experiments with red light and zooxanthellae in the late 20th century. He realized red light was a regulating mechanism for either the number of zooxanthellae and/or the content of their photopigments (chlorophlly a, c2, peridinin, etc.). In laymen's terms, this regulation is referred to 'bleaching'."

And, "other peer-reviewed works have confirmed coral growth is greatest when corals are maintained in conditions of deficient (natural) amounts of red light."
 
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