Green and amber are not neccesary for photosynthesis and white LEDs have plenty of red in them. Even if there was such a thing, most people don't even want true sun like full spectrum cause your corals wouldn't look as nice.
What I don't think a lot of people realize is that white LEDs have enough red to be able for our eyes to pick up, but cool white LEDs have much less GaN phosphor, trading non-blue spectrum for, uh, blue (white LEDs are just royal blue LEDs with a layer of phosphor over them).
You also don't seem to realize that you can have this extra spectra applied without losing the 'look' of a fixture, or losing fluorescent pigments, etc. No one is trying to mimic the sun exactly (LEDs can't because of their narrow-spectrum nature), but remember that the sun emits far more green and red light than it does blue at sea level - even adding a dozen red LEDs to 50 blue LEDs won't make it to where corals don't 'look as nice'.
I have trouble understanding all the details of all the LEDs out there, I posted that the 6500k was a neutral white, I did read that somewhere but can't find the link now but they referred to 6500k as neutral white because it was the closest to natural sunlight color temperature, the highter Kelvin was referred to as cooler and the lower Kelvin as warmer, I also know that 6500k is referred to as cool white in other forms of lighting such as compact fluorescent...didn't mean to mislead with that previous post....
Yeah, most people just aren't informed about them (there is a lot to know). No biggie, that's what the internet is for
from what I've read, the only LEDs needed to grow coral are royal blue and 50/50 mix of 6500k white or royal blue and 67/33 mix of warmer white, the higher Kelvin whites are useless for a reef tank and the red, green, and yellow are added with the 6500k white to enhance our visual pleasure and not really beneficial to the coral and not really necessary with the warmer whites either.......
You can grow corals in just about any light. Heck, people used 6500K Iwasaki halides, which have the most horrendous spectrum I've ever seen (see
here for details on that). People have used all 480nm, all 450nm, all cool white, etc, and all grew corals like weeds as long as the intensity was there. You need less intensity of blue light in comparison to what you need if you used cool white only, since corals really only use blue light (428nm mostly, then 448nm, then 470ish-nm) and the cool white 'waste' energy beyond 500nm. Of course, almost all corals look like garbage under just blue light, as blue light has a CRI of zero.
this is all still way over my head, I'm still learning about the LED technology and still have a long way to go to fully understand it all, but I know I don't like the looks of the warm white in my tank, the 6500k looks much better to me and I know that's why they recommend twice or more of the blue LEDs to the warmer whites to offset the yellowish look of warmer whites....
And again, non-fluorescent corals look better under warmer whites otherwise some of their colors (typically those reading over 600nm in reflected color) will not be 'excited' enough to even show up. It's why corals without a lot of fluorescence look better under halides and T5s than arrays with cool white and royal blue LEDs.
I know that my LEDs are Chinese made but my coral looks great and seem to be growing just fine, these LEDs use less than half the power my halides did and produce virtually no heat, these didn't cost as much as the high quality DIY kits I looked at and look a lot better than anything I could DIY and they are a boat load cheaper than some of the brand named LEDs on the market....
I also know they say that these are not as efficient as some of the Cree based DIY kits and don't have the flexibility that a DIY kit offers but they are more efficient than halides and if they last a year, then I'm ahead cost wise in the power that my old halides didn't consume and the bulbs that I didn't have to replace...
Compared to Luxeon Rebels, they are aren't that much of a bargain. Rebels consume less energy overall, emit at least twice the light, and cost only a bit more than the typical 'Chinese' LED. Cree has around the same output (in some cases less) but at a higher cost, so the difference becomes larger.
That all being said, they are more efficient than halides and T5, using a bit over half the wattage to get the same amount of light, but also without the harmful UV and insane IR (and therfore heat).
I never said we shouldn't listen to what he has to say. I'm just saying that maybe once and a while he gets so far off into the weeds of minutia that people worry about stuff that really doesn't matter. When you buy that new 2013 Mustang, do you really care if the paint is DuPont or Imron, or if the tires are Goodyear or Bridgestones? Do I care that much if my white leds are properly binned or not? You may, and that's fine. I'm just saying a lot of people only care if the light is well built and the corals will be healthy and grow. If the led is going to make my red coral a slightly different shade of red, I really don't care. I'm just glad to be rid of my MH and t5 bulb addiction!
"Weeds of minutia", eh? If you don't give a **** about what is going on in your tank and just want corals to grow, that's fine and dandy, but there are those of us that do want to know and want to know how to optimize growth and looks, and possibly want to help others do the same. I'm sure you can find the door.
I never understood what the bin thing was.....and I'm not trying to be a smart tail, just curious and would really like to know
is that something like, they test each and every LED and put the identical spectrul LEDs in their own seperate bin or what's the deal with that ?
and if that's what it is, do they toss all the odd colored LEDs in the garbage ? or are they in the next bin with more just like 'em ?
Binning is where they determine the color temperature, CRI, dominant wavelength (if it isn't a white LED), output, forward voltage, etc. It follows a pretty standard bell curve - 70% of all the LEDs in the wafer will be 'average', some will be good/bad, and some will be awesome/crappy (for either side of the bell curve). They're separated and priced accordingly. A lot of the knockoff LEDs, though, will not be binned at all, and can vary wildly in not only output, but in color. Most '6500k' knockoffs, if measured, will actually be much cooler.
Oh I fully agree some of the details such as the binning and slightly changing the shade of some corals are not necessary and get in the way of a basic question (at least in this post - not in general. I really appreciate his knowledge). However, I think the part about what spectrum corals need for photosynthesis and what the peak absorption wavelengths are is incredibly important - that is what determines how much of the light you are shining on your corals they can actually use! And 100% directly related to how much growth you will get and what kind of colors you will get. And, it is simple to understand - freshmen level high school biology.
Sure, buying that new mustang gt you don't care where the paint comes from (well some people do), but you DO care if you have that new 5.0L 420 horsepower engine or the 2 year older 4.6L with 100 horsepower less that cost the same price! That is the kind of importance that the power and led colors have on your coral growth.
Sure - the OP doesn't need to know any of the binning information or anything like that - but at least, IMO, he should know the basic lighting requirements of his corals, and the rudimentary reasons why - as should anyone who keeps them.
Well said!
