# Cool White LED/Blue LED danger-blinding fish?



## BlueJack (Apr 15, 2011)

I was doing research online to find the perfect led setup over my tank and came across some interesting info. 

According to wikipedia "there is concern that blue LEDs and cool-white LEDs are now capable of exceeding safe limits of the so called blue-light hazard as defined in the eye safety specifications. *Blue-light hazard* is defined as the potential for a photochemical induced retinal injury resulting from radiation exposure at wavelengths primarily between 400 nm and 500 nm.(I believe blue led moonlights peak around 460nm, and a substantial part of cool-white led spectrum is in that 400-500nm range). The mechanisms for photochemical induced retinal injury are caused by the absorption of light by photoreceptors in the eye. Under normal conditions when light hits a photoreceptor, the cell bleaches and becomes useless until it has recovered through a metabolic process called the visual cycle. Absorption of blue light, however, has been shown to cause a reversal of the process where cells become unbleached and responsive again to light before it is ready. This greatly increases the potential for oxidative damage. By this mechanism, some biological tissues such as skin, the lens of the eye, and in particular the retina may show irreversible changes induced by prolonged exposure to moderate levels of UV radiation and short-wavelength light.

I know your not supposed to believe everything you read, so can someone please discredit this since I love the look of a cool-white led over a tank and my moonlights. Although, if my fish will be blinded by 12 hrs of cool-white daylight followed by 12 hrs of blue moonlight, might have to make some changes.


----------



## HypnoticAquatic (Feb 17, 2010)

ultra violet is propbably what your thinkin of and that can an will blind fish and us that has been proven. uv light is on the lower side of the 420nm down to 360 ? the lower it is its harder for us to see but still exists. so idk what nm they are really worried about because i havent blinded any of my fish and i have a insanely bright light thats only blue and red. i would do more research on your part befor i would belive that just my thoughts


----------



## psalm18.2 (Oct 16, 2010)

I know they hurt my eyes. Don't know about fish as they don't look up.


----------



## Steve001 (Feb 26, 2011)

BlueJack said:


> I was doing research online to find the perfect led setup over my tank and came across some interesting info.
> 
> According to wikipedia "there is concern that blue LEDs and cool-white LEDs are now capable of exceeding safe limits of the so called blue-light hazard as defined in the eye safety specifications. *Blue-light hazard* is defined as the potential for a photochemical induced retinal injury resulting from radiation exposure at wavelengths primarily between 400 nm and 500 nm.(I believe blue led moonlights peak around 460nm, and a substantial part of cool-white led spectrum is in that 400-500nm range). The mechanisms for photochemical induced retinal injury are caused by the absorption of light by photoreceptors in the eye. Under normal conditions when light hits a photoreceptor, the cell bleaches and becomes useless until it has recovered through a metabolic process called the visual cycle. Absorption of blue light, however, has been shown to cause a reversal of the process where cells become unbleached and responsive again to light before it is ready. This greatly increases the potential for oxidative damage. By this mechanism, some biological tissues such as skin, the lens of the eye, and in particular the retina may show irreversible changes induced by prolonged exposure to moderate levels of UV radiation and short-wavelength light.
> 
> I know your not supposed to believe everything you read, so can someone please discredit this since I love the look of a cool-white led over a tank and my moonlights. Although, if my fish will be blinded by 12 hrs of cool-white daylight followed by 12 hrs of blue moonlight, might have to make some changes.


That's true for human eyes. But for fish eyes can't say. I'm almost sure a search will bring up something

Personally I know it's best if you give your fishies a period of complete darkness. Just like us for their health.

I've seen these so called Moon lights and I can't see why there sold as simulated moonlight. I could see it if tanks were impractically deep, but home aquariums aren't. Typical home tanks don't come close to blocking out all wavelengths except blue. Simulated moonlight should be a dim stark white light. The moon is waxing here in the states just take a look at it; it's not blue


----------



## Hoppy (Dec 24, 2005)

Steve001 said:


> Simulated moonlight should be a dim stark white light. The moon is waxing here in the states just take a look at it; it's not blue


Except when it is a "blue moon"?:hihi: I think "moonlights" are blue just because people like the way it looks, and how it can make fish like Cardinal Tetra's look.


----------



## madhatter4 (Dec 13, 2007)

Ive had blue and white "moon lights". To me, the white looks better and is more natural but for some reason the blue is easier to see whats going on in the tank.


----------



## Steve001 (Feb 26, 2011)

Hoppy said:


> Except when it is a "blue moon"?:hihi: I think "moonlights" are blue just because people like the way it looks, and how it can make fish like Cardinal Tetra's look.


If it was a _blue moon_ then it only be appropriate to use blue led's once in a calendar season every few years. :wink: 
I like blues; it's my fav color too but not for simulated moon light. On the other hand it might or would be appropriate for deep water tanks. I'm about as convinced as you that blue led's are sold for aesthetics over function because people like blue.


----------



## Gig'em (Apr 8, 2010)

I don't think moon lights are practical at all when it comes to aquariums. Sure it looks cool and allows you to see at night, but if you're trying to make it more "natural", the moon lights don't achieve that goal. If anyone has gone night diving on a reef they know that once you turn your flashlight off it's like floating in space, no light at all. It's kind of a terrifying and beautiful experience, but I couldn't see my hand an inch from my face. And in freshwater, I go swimming in a spring fed lake at night when I visit family in MN and I can't see the sand in 3 inches of water at night even with a full moon. 

I know this thread isn't about moon lights, but that's my opinion. I wonder if the water would have any effect on that study since water can reflect and absorb some of the light waves and maybe they can absorb the more harmful spikes of light that would otherwise cause damage when viewed directly out of the water. 

Fishes eyes are also different than our own, so I'm not sure if they are even negatively effected. I would be more worried about my eyes for the amount of time a day I spend staring at the tank :hihi:


----------

