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crn005
07/23/2014, 10:04 PM
So what is y'alls experience with Lime LEDs? I tried looking for threads about them but haven't gotten much results. Any experience? Comments? What do y'all think about them?

mkj
07/23/2014, 11:09 PM
I don't believe they offer any usable spectrum for coral growth. They just take the blue out of the white led. I think the theory is that most aquarists are using separate blue spectrum LEDs so no need to add more of that spectrum. I believe some blue spectrums are bad for the human eye and there's a danger when looking at a tank with too much. By using the Lime/RB/B combination instead of white/RB/B combination it may do less damage to our eyes.

Ron99
07/24/2014, 10:06 AM
I don't believe they offer any usable spectrum for coral growth. They just take the blue out of the white led. I think the theory is that most aquarists are using separate blue spectrum LEDs so no need to add more of that spectrum. I believe some blue spectrums are bad for the human eye and there's a danger when looking at a tank with too much. By using the Lime/RB/B combination instead of white/RB/B combination it may do less damage to our eyes.

What????? Where in the world did you hear that? It makes no sense. Blue LEDs don't hurt our eyes.

mcgyvr
07/24/2014, 11:25 AM
What????? Where in the world did you hear that? It makes no sense. Blue LEDs don't hurt our eyes.

Ron, you might want to read this then...
www.cree.com/xlamp_app_notes/led_eye_safety

To date, the testing shows that
Cree’s blue and royal blue LED
components (450-485 nm dominant
wavelengths) pose a higher
potential eye safety hazard than
its white LED components


Oh and I like the lime because they taste better than the orange LED's :)

Ron99
07/24/2014, 12:14 PM
I think that likely applies to looking more directly into the LEDs than looking at a tank lit by them and seeing reflected light. Any sufficiently bright light source has the potential to damage your eyes if you look directly at it for long enough. There should be no danger in looking at tanks lit by blue LEDs as you are not getting the full intensity directly into your eyes but only a fraction of the light reflected back.

reefgeezer
07/24/2014, 12:17 PM
No experience here but... IMO, lime LEDs help with color rendition. @ 565-570nm, they don't emit photons usable to most corals. They should make greens and yellows look better though. If you don't have issues with those colors now, the Lime LEDs may not change anything. If however, you system is too blue and the yellows & greens don't look right, lime LEDs might help. NW or WW LEDs can do the same thing. However, the lime LEDs may also make some corals fluoresce.

ken6217
07/24/2014, 12:22 PM
And don't be shining your lights at airplanes! :)

mkj
07/24/2014, 05:06 PM
You got to remember we tend to stare at our tanks not just walk by them. I'm not an eye doctor but have read many times that short wavelength "any blue" does more damage to human eyes than other wavelengths "especially in LED lights" because they are more of a direct light even after reflection.

Yes looking directly into any light is bad "this is obvious" but it has been found that even indirect light from Blue LEDs can cause damage, because they are not a soft light.

Hopefully an Eye doctor can chime in that knows more than I.

reefgeezer
07/24/2014, 06:32 PM
You got to remember we tend to stare at our tanks not just walk by them. I'm not an eye doctor but have read many times that short wavelength "any blue" does more damage to human eyes than other wavelengths "especially in LED lights" because they are more of a direct light even after reflection.

Yes looking directly into any light is bad "this is obvious" but it has been found that even indirect light from Blue LEDs can cause damage, because they are not a soft light.

Hopefully an Eye doctor can chime in that knows more than I.

Not an eye doctor but I stayed at a Holiday Inn a couple of weeks ago...

Blue light can cause do damage simply because the human eye perceives it as dimmer. We may not realize how bright light in the 400 to 470nm wavelength really is and stare at it longer. That said, the blue light in the tank is not too bright unless you are looking directly into the emitters.

Also, adding a lime LED doesn't cancel out the blue photons, it only changes how we perceive the color. If they were dangerous, they would still be there.

mkj
07/25/2014, 12:59 AM
I found a couple articles about the blue wavelength in LEDs that explains the accumulated danger better than I could. they mention the exposure length as being the real problem not the intensity. The most harmful is between 415-455nm. Because the emission surfaces of LEDs are highly-concentrated point sources, the luminance of each individual source can be 1000 times higher than the discomfort level. Even a deflected Blue LED can cause much more damage to the eye than other wavelengths do to its ability to penetrate our retina.

Blue light causes a photochemical risk to the eye, says the report, the level of which depends on the accumulated dose of blue light to which the person has been exposed, which is generally the result of low-intensity exposure repeated over long periods. "Blue light is…recognized as being harmful and dangerous for the retina, as a result of cellular oxidative stress," says the report, adding that 3 groups are particularly at risk; children, populations which are already light-sensitive, and workers likely to be exposed to high-intensity lighting (Aquarists).

Blue light, which is part of the visible light spectrum, reaches deeper into the eye and its cumulative effect can cause damage to the retina. Furthermore, in certain wavelengths, blue light is implicated in the development of age-related macular degeneration (AMD).

Just something to think about when looking at our tanks. What's good for corals doesn't seem good for us especially after adding all the other tech stuff we look at every day such as monitors, smart phones.

Ron99
07/25/2014, 01:14 AM
Do you have links to those articles?

mkj
07/25/2014, 02:38 AM
sorry, I took the links down because I'm not sure I'm allowed to post them without reefcentrals permission.

Google is our friend though, so search something like "problems with blue LEDs" and many articles I referenced should show up on first page

stancfii
07/25/2014, 02:49 PM
Lime is more for color rendition. It allows us to perceive the tank as being brighter, without us having to crank up the amperage on the wave lengths that will burn corals when they are at our desired level of brightness. They aren't necessarily intended to replace white LEDs, they just supplement them and provide a good peak around 540-550 that is present in nearly all MH, but lacking in most LED fixtures. The guys who are using them say that it has finally made LED as good or better than halides. I'm going to throw a couple in an old fixture and see what happens. The advice, however, has been to use them sparingly, as in 1 lime for every 3 or 4 of your other whites.

crn005
07/25/2014, 05:27 PM
Does anyone have some with and without pictures? I'm curious about the change it does to rendition.

As far as eye safety goes, if staring at my tank makes me blind, then bring on the seeing eye dog!

reepher315
07/25/2014, 07:59 PM
There are green led's on my 165w. You can tell in the shadows there are green lights even though there are only 2 out of 50. It does seem to make the green/yellow coral more visually appealing.

bdevillier
07/25/2014, 08:27 PM
lime leds are useful in lighting our tanks. there have been quite a few recent builds on other sites using them and demonstrating how well they work. they are not the same as green leds. when grouped in tight clusters some have found to run them in a 1:1 ratio with the whites to improve the overall look of the tank. from what i have seen it gives tanks more of the metal halide look (as said by others, not myself). look up jedimasterben's light on the nano site and see what he has done. photos galore and par readings to go with.

reepher315
07/25/2014, 08:29 PM
Oh ok sorry for the confusion between green and lime. Ill have to look more into this.

Ron99
07/26/2014, 12:59 PM
I had a look at some journalistic articles and a quick look at a few medical papers. It seems to me that this blue led danger is a story that is based on one study in spain that likely doesn't correlate to the real world. The spanish study was the equivalent of someone looking at a 100watt light bulb, at a distance of 12 inches for 12 hours a day.

So unless you are sitting and staring at your tank non stop all day I wouldn't worry. Don't stare directly into the LEDs as yes, they are strong point sources of life. But the same could be said of MH etc. Don't stare straight at the light. But I doubt that the replected light from our tank, even from all blue LEDs is harmful to our eyes.

And I can see how the lime LEDs will add to the overall visual spectrum and the look of our tanks. But I don't see them as a replacement for blue. That still wouldn't look right.

stancfii
07/28/2014, 02:57 PM
The itch got too strong...I ordered a couple of lime LEDs today. I hope to have some results to post by the end of the week.

crn005
07/28/2014, 05:35 PM
The itch got too strong...I ordered a couple of lime LEDs today. I hope to have some results to post by the end of the week.

Nice! Please post your results.

crn005
07/28/2014, 06:15 PM
I just thought of another question. Someone made the comment earlier about the green lights and banding issues. I've had those issues as well. Y'all said that the lime blends perfectly with whites, but does it help tie everything in? Does it improve blending issues with other colors? The only complaints I have about my LEDs is that no matter how tight I put them (literally all touching each other) there is always slight blending issues.

stancfii
07/28/2014, 08:32 PM
I really don't think it will help with blending. It may help a little, but not much if at all. The only way to help with blending, after you tighten them as much as possible, is to raise the fixture.

crn005
07/29/2014, 10:48 AM
Are y'all using lenses on your lime LEDs? I'm about to order some and I was curious.

stancfii
07/29/2014, 12:55 PM
I haven't seen any build threads where people are using lenses on them. I don't intend to because I have a shallow tank (16"). I certainly wouldn't put lenses on them if you have concerns about color separation or banding.

stancfii
07/31/2014, 01:42 PM
Got the lime LEDs in the mail today, and slapped them in my fixture. At the level I run my white channel (enough to turn on), I can't tell a difference. If I crank it up, I can tell it looks more 10k, but I really don't think it was worth me spending $10 on to try out. I think these may not make much of a difference on my fixture because I use 5000k Philips with a cri of 85, so they have a fair amount of that spectrum anyway. I'd post pictures, but I couldn't see a difference between them.

crn005
08/04/2014, 06:27 PM
I got mine in last week and popped them in on Friday. Anyway, I'm a big fan of them. I am running four limes and four neutral whites on the same string. Honestly, I'm going to put a couple more in and take the neutral whites down to just two. When I turned that channel on first, I saw a bright yellowish green glow on the wall behind the tank. Once the blues turned on, it turned into a nice, crispy white. It took the purplish hue out of my lights and gave a much more natural color to the tank. I'm excited to see where the industry goes with these lights. I'm looking at you, Borealis Luxeon Z. Get some optics and I'm buying!

mcgyvr
08/04/2014, 06:35 PM
I'm looking at you, Borealis Luxeon Z. Get some optics and I'm buying!

Just saw that thing the other day.. Why did they group the LED colors like that? totally silly IMO.. I'd bet you easily see the color separation on the sandbed with that.

crn005
08/04/2014, 07:49 PM
Just saw that thing the other day.. Why did they group the LED colors like that? totally silly IMO.. I'd bet you easily see the color separation on the sandbed with that.

Eh, I doubt it. The whole puck is 2.5" x 1.75". Those babies are jammed in tight. Even the radion puck's are 3" x 2 7/8". Just the grid alone on radion pucks is 3" x 2".

stancfii
08/05/2014, 12:24 AM
Glad they are working well for you! What brand of whites are/were you running?

crn005
08/05/2014, 11:20 PM
I do believe they are the CREE XP-G 5W. I got them as a part of a kit from rapidled last year but I don't think they use those in their kits anymore.