Yep if you look at the ocean, where there is red light there is algae. Once you penetrate the ocean deep enough the "red" light is the first that gets filtered out. Hence after a certain depth...no algae's like there is towards the surface.

In a tank it means nothing, our tanks are not deep enough to do this... I sorta think the spectrum claims of LED manufacturers admit of a bit of snake oil i'm afraid, rather their claims of perceived benefit...but again LED is relatively new...so time will tell.

Something I've read on other forums say that the full spectrum is not mainly used to improve growth. You can have a perfectly healthy and growing coral under just Blue and White LEDs. However, they pointed out that there are some other photosynthetic pigments in coral that will will peak at other light wavelengths. By giving those pigments the wavelength they peak at, they will supposedly show better color overall.

Not my opinion, just something I've read. I'm still trying to decide whether or not the Full spectrum is worth it for my next upgrade. Personally tho, I've had a few coral change color on me with my current T5s, some of them came from Blue/White LEDs, some of them came from T5s. So I'm not sure what to believe.

LED does allow for a tweaking of the view able light for corals...thus the ability to alter their aesthetic....however I do no think that it can match a good MH and Actinics (Yet - and certainly in my opinion) .... But again, the problem with the rapid replacing of LED fixtures is to obtain the latest and greatest, as the tech is not mature. Thus as one aspect changes others do as well. I think LED will be the top due to all of the benifits it "WILL" have eventually. Even I will switch when they are there....I just don't think they are...proved i think by the continuous and rapid changes in development - eventually as the tech matures i think development cycles will slow....LED is hot in general and the tech improvements are great and rapid paced - in such an environment there will always be "reason" to upgrade I think - though I suppose if you are happy and don't want the latest and greatest - But the Marine Aquaria industry jumps on the new thing and pushes and pushes...it knows a cash cow when it sees one.

I am going to try a couple of LED pendants as sort of a spot lightning or highlighting effect....when i build the system as the pendants were free - so maybe I will convert. But the 'perceived" downsides to MH were never a problem for me.

I have seen as many people in support of LEDS as there are people who went back to MH,t5 from LEDS - Choice is good and there is an abundance of choice in lighting.

Many zooxanthellate corals have their bright colors because of a family of multi-hued fluorescing proteins. These pigments seem to be produced in response to a given light environment. The primary control on their production appears to be total irradiance level, and little evidence exists to suggest that the "k" rating of bulbs will influence their production. There is also a strong genetic component, although the specific aspects of fluorescing proteins and their respective genes have not yet been worked out. The color temperature of light bulbs most likely influences the perceived color of corals in a tank, with ultraviolet components enhancing highly fluorescent pigments. Certain bulb temperatures may have enough of their spectrum skewed in relative distribution that total irradiance with a given wattage may be affected, and thus total irradiance influencing the relative production of fluorescing proteins.


Above COURTESY OF http://www.reefkeeping.com/issues/2003-11/eb/index.php - it is an older article, and indeed more may have been learned on the matter.

http://www.nightsea.com/articles/publications/

Full spectrum is basically entirely for coloration.

Advanced aquarist has a good review on fluorescence, and fluorescent pigments in corals. This has been thoroughly discussed in scientific literature (and continues to be discussed). (http://www.advancedaquarist.com/2006/9/aafeature) If you guys take a look at figure 2, it highlights the broad spectrum of wavelengths (both visible and UV) that fluorescent pigments in coral cover--the more of them we hit with our light's emission, the more vibrant our corals look.

In terms of growth, there are photosynthetic pigments that absorb into the visible as well (and even approaching the near IR... or well into the red), but the most common ones (the chlorophylls) absorb around the wavelengths that 'blue' and 'white' LEDs emit. http://reefbuilders.com/2010/08/23/c...nfrared-light/

The reason people switch back to T5 and MH light sources is because these lamps are broadband emission sources, so you're hitting both the growth wavelengths and the other visible wavelengths all with one lamp, resulting in growth AND pretty colors. LEDs are narrow band emitters (ie: they just hit specific bands), so including different colors of LED
helps with color rendition. LEDs have other advantages; smaller fixtures, run cooler, use less power, long bulb lifetime, etc.

As a guy who works on LEDs on the molecular level, I'm stoked about the technology. Sure there's room to grow, but people hanging onto MH and T5 systems may be a little afraid of change. ;)

Excellent, will have to do some more reading.

All worthwhile advantages, as long as it is not at the expense of the corals.

Energy saved seems moot when every six months people seem to be upgrading :twised:

Wary of change maybe but not Scared. I prefer ...so far at least ... the look of MH over that of LED. Again its a trusted method and I have no problem saying it could be because I am used to MH. but I didn't switch to T5 over MH either. The look is not the same. LED is nice but again I don't think its there yet. Again, in Marine Aquaria the "next" thing is always pressed as more advantageous...it makes money.

Again...I'm going to try LED again and see....especially if it warrants it after reading.


But again, people are replacing their fixtures because itr is the newest thing, the newest thing is always pushed and "improved" periodically. Again, I am not as current with LED as you probably are, but It's not a mature tech yet....so again the developments will come rapid for the next little bit i would think.


I must say i like the Aesthetics above the tank with the LED pendants...its the inside i worry about. I have Orphek Pendants and Kessil a350's the adjustable ones....having them hanging down over my rimless tank would look awesome...if they make the livestock look good then I'll not hesitate in switching.

Just a slight correction. Chlorophylls a and b absorb best at about 475 and 680 nm. They utilize energy from 680 nm photons more efficiently than at 475 nm as the former have an energy content closely matching the ideal level of chlorophyll excitation. In terms of growth, we are primarily concerned with chlorophylls a and b. The more colourful pigments (carotenoids) serve more of a photoprotective role and do not have a major impact on growth, at least in algae.

White LEDs as I'm sure you know are a mix of wavelengths. So you can't say a pigment absorbs best at the wavelengths white LEDs emit, since they emit a very broad spectrum.

so I'm getting nothing specifically wrong with the AI Sols, other than maybe aesthetics re:SPS

No nothing at all wrong with them. Growth is great and color is good.

Unfortunately it seems lately any thread started with leds in the title attracts all the people with no experience with them to feel the need to tell everyone what's wrong with all LEDs.

No, not even that. They're fine. If you stood in front of my tank, you'd agree they do a decent job with SPS.

Haha my thoughts exactly. Well put. I like my Sols. Big learning curve and would buy them again.