thatguy559
Well-known member
i have been reading about the effects of uv leds and what they do for corals. i was wondering your thoughts on this
uv leds
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I have one of the cheap 3w ones from kaidomain over my 3g; when the blue and white strings are on you can't even see any difference turning the UV on and off and I don't think it does anything useful as far as coral color and growth. With the lights off though you can get some crazy effects, sadly its impossible to take pictures of...
To get something that would be in the same ballpark as MH UV output you'll need to get some "real" high power UV LEDs that will be over 100 bucks each, not really feasible at this point and I haven't heard of anyone trying it yet.
To get something that would be in the same ballpark as MH UV output you'll need to get some "real" high power UV LEDs that will be over 100 bucks each, not really feasible at this point and I haven't heard of anyone trying it yet.
thatguy559
Well-known member
from liveaquaria.com
Color change due to UV light
In nature, ultraviolet light waves (UV-A and UV-B) penetrate the ocean's surface but are filtered out as the light travels through the water. Both UV-A and UV-B light waves have been found to cause destruction of DNA and RNA within coral tissue. In response, many corals have made adaptations to reduce the effects of these harmful rays. These corals developed protective pigments that are often blue, purple, or pink in color. Most corals that contain these pigments come from shallow waters where the amount of UV-A and UV-B light is higher than in deeper areas of the reef.
In home reef aquariums that rely on metal halide lighting, it is important to protect corals from UV light. Coral without these protective pigments as well as shallow water corals that may have lost their pigments during transportation are especially susceptible to the effects of UV light. Fortunately, preventing any UV light from entering the aquarium is as simple as employing glass aquarium canopies and making sure the protective glass lens on the metal halide fixture is properly installed.
It is not uncommon for corals with these bright colors to adjust to the lower UV-A and UV-B conditions found within home aquariums. The loss of colorful pigmentation is not necessarily a sign of an unhealthy coral - it is simply a normal coral adjusting to its new environment.
It is a common misconception among many hobbyists that color changes in newly received coral is an indication of unhealthy coral. Many times the color change is merely the result of corals adjusting to the new lighting intensity, spectrum, and change in UV light. With this in mind, it is important to consider the color of newly received corals and understand their lighting requirements. Be sure to properly acclimate corals to new lighting conditions and allow time for them to establish their coloration.
Color change due to UV light
In nature, ultraviolet light waves (UV-A and UV-B) penetrate the ocean's surface but are filtered out as the light travels through the water. Both UV-A and UV-B light waves have been found to cause destruction of DNA and RNA within coral tissue. In response, many corals have made adaptations to reduce the effects of these harmful rays. These corals developed protective pigments that are often blue, purple, or pink in color. Most corals that contain these pigments come from shallow waters where the amount of UV-A and UV-B light is higher than in deeper areas of the reef.
In home reef aquariums that rely on metal halide lighting, it is important to protect corals from UV light. Coral without these protective pigments as well as shallow water corals that may have lost their pigments during transportation are especially susceptible to the effects of UV light. Fortunately, preventing any UV light from entering the aquarium is as simple as employing glass aquarium canopies and making sure the protective glass lens on the metal halide fixture is properly installed.
It is not uncommon for corals with these bright colors to adjust to the lower UV-A and UV-B conditions found within home aquariums. The loss of colorful pigmentation is not necessarily a sign of an unhealthy coral - it is simply a normal coral adjusting to its new environment.
It is a common misconception among many hobbyists that color changes in newly received coral is an indication of unhealthy coral. Many times the color change is merely the result of corals adjusting to the new lighting intensity, spectrum, and change in UV light. With this in mind, it is important to consider the color of newly received corals and understand their lighting requirements. Be sure to properly acclimate corals to new lighting conditions and allow time for them to establish their coloration.
thatguy559
Well-known member
coloration of coral seems to be directly related to UV exposure and is a genetic mutation that helps protect their supporting algea.
I read that LED's don't produce the green and yellow spectrums that corals don't use, only red slime cyano uses the green and yellow. If that true than cyano would go away under LED's. Check out this article, you may have already seen it as I posted it on my led vs. MH thread. This article also talks about how LED's don't produce UV-A light so it's easier on the corals and us.
http://www.americanaquariumproducts....ng.html#lumens
http://www.americanaquariumproducts....ng.html#lumens
tat2z_21
tat2z_21
I read that the UV LED's wave length is actually above the UVA wavelength range being at 400 to 410nm. Germicidal UV has a wavelength of 10nm to 100nm.
thatguy559
Well-known member
i want to add uv lighting to my tank to get better coloration in my corals
http://www.superbrightleds.com/cgi-...age&category=BARS&Page2Disp=/specs/LBM-x2.htm
under the uv section
http://www.superbrightleds.com/cgi-...age&category=BARS&Page2Disp=/specs/LBM-x2.htm
under the uv section
This is correct, many of the inexpensive UV LEDs are technically just really deep purple, which is usually considered to go down to 400nm. 400-410nm is all but invisible to our eyes though and all you see is coral fluorescence, so it seems like a blacklight/UV effect.
As far as those UV modules go, each module is only about 1/8 of a watt of output power to the LEDs. I have 25 times that much UV over my tiny 9x9 tank and it doesn't seem to do much that the royal blues don't do already, the current generation of UV LEDs just isn't very efficient or powerful... They would make killer moon lights though.
Ok iv'e been swimming in the LED pool, and am very confsed now. Can you gorw healthy SPS tanks with LED's alone or not?
It seems that there are many different types of LED's out there. Which ones will provide enough light for a stable reef tank? or do they just not exist yet?
It seems that there are many different types of LED's out there. Which ones will provide enough light for a stable reef tank? or do they just not exist yet?There are many people keeping SPS under LEDs alone, myself included, and the simplest successful setups usually have combinations of royal blue and cool white. You can add in other colors as well (I've seen people do UV, cyan, green, neutral/warm white and red) but the effect of doing so is not well understood at this point.
Getting them to throw enough light is not a problem, most people actually end up dimming their array back a ways to prevent bleaching; I keep mine at less than 50% power.
Getting them to throw enough light is not a problem, most people actually end up dimming their array back a ways to prevent bleaching; I keep mine at less than 50% power.
Ok, so if I understand. LED users have to buy a lot of LED's to cover the tank ($$$$$), and then back off the light because there's to much concentrated light on the corals. So LED's are powerful and work well if you've got the cash? am I right on this?
thatguy559
Well-known member
how did this thread turn into a led fixture thread.??????i simply was asking if anyone knew about adding uv led's as supplement lighting to bring the colors out more in my corals
thatguy559
Well-known member
so the uv leds produce light at the 405nm wavelength which means its just at the beginning of the visible light spectrum. the harmful uva/uvb range is 280-400nm. not sure if these leds weill replicate the suns uv rays that cause the corals to produce brighter colors.
Also I will add that the UV filter glass used with halides only attenuates most of the UV-B and UV-C regions, it is mostly transparent to UV-A and halide powered tanks should theoretically be getting significant amounts of UV-A depending on how much the bulbs are putting out.
thatguy559
Well-known member
here is a picture with uv and actinic leds on
tat2z_21
tat2z_21
Do you have a before the UV'age to compare too. Because from what I remember your tank was always pretty bright
thatguy559
Well-known member
ok so a little update. some of my zoanthids have gotten more intense coloring on them. my fish appear to be brighter. the one i noticed was my blue jaw trigger she didnt have any coloring when i got her now she has yellow fins and a bluer jaw.
