Coral fluorescence, which UV light?

Icefire

Seasoned reefer
For night viewing, which nM range will peak the fluorescence in GSP/Hammer/Zoa/etc?

I guess only UVA is safe so in 320 to 400nM ?

I can get leds in 5-10nM increment, so which is best? 385-395?
 

Frick-n-Frags

New member
what a cool experiment

you should try several throughout a range to see which color lights 'em up the best. the only comparison I have is flourescent black light vs actinics and the VHO actinics were far higher output so they lit everything better, but not a fair test.

I would start at 450 to get a feel for the whole range all the way to whatever 350 in increments of 10. then you could plot what probably will look like a bell curve and that should indicate the sweet spot. you should use different corals too, and different hot colors.

I doubt anyone commonly knows this information around here.
but a link to a test could always still show up
 

Aquabucket

Premium Member
Most black lights peak @ 360-380 nm. Pure actinics peak @ 420nm. There will be less visible light as you get closer to 360.
 

Frick-n-Frags

New member
his question isn't about visible light, i don't think. I think it is about which specific freq flouresces the corals the most. it could very well be the nearly invisible shorter UVA, or higher up the blue.

just think if it was at 350, on an LED humans can barely see.
the progressive light sculpteur :D might be able to sequence some to make the corals look like they glow then fade periodically
heh.

i wonder if certain frequencies light up different colors better like zoanthid orange vs sinularia green vs monti screaming pink or whatever.
 

Aquabucket

Premium Member
Things appear to fluoresce more with less visible light. A true black light with cobalt glass filters placed in a completely dark room with black walls would show nothing and the room would remain dark. The amount of fluorescence is going to depend more on the intensity of the bulbs and not so much its wavelength in this range. You were right the first time with regard to experimentation. The best way to find out is to try out the various bulbs offered.

Another factor at play is the quality of the subject matter in this case it would be the corals.

To get a better understanding on how black lights work here is a simplified explanation. Normal pigments under regular daylight reflect about 20% of the dominant color. In other words a red pigmented surface for example under normal light has a wide range of colors being reflected but the dominate color ~ red in this instance only dominates the other colors by 20% more giving us the color red. Now take that same surface and cover it with a fluorescent pigment such as red and illuminate it with a light in the black light range and the dominant color radiates at up to 80% yielding a much purer form of the color red.

The purest forms of color are light generated and not pigmented surfaces illuminated by light. Lasers and electrically charged gas (plasma) offer us the purest forms of color.
 
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Aquabucket

Premium Member
Here is some more info for you to take in.

When it comes to reef lighting many think VHOs provide the best light for fluorescence. VHOs are the closest bulbs to the black light range and have the least amount of visible light as opposed to other types of bulbs offered. The problem is when you go to this range it takes more energy to gain intensity and these bulbs can appear to be dimmer than others that radiate more visible light.

An HO T5 ATI Blue Plus bulb (peek = 450nm) probably has the highest intensity of all the fluorescent bulbs offered in this range but they contain higher amounts of visible light which somewhat diminishes the "fluorescent effect" we see in VHOs. Its the lack of visible light in VHOs that gives us a wider contrast between light and subject matter.

Now lets get back to the subject matter in this case it is corals. In nature most fluorescent pigmented corals that are excited by light in the high UV range radiate fluorescent color in the green spectrum. Corals with colors such as red, orange, & yellow generally are not as fluorescent in nature with some exceptions. To bring out these colors more ~ a certain amount of visible light is desired.

For this reason a blending of bulbs is the best way to get a wider variety of corals to "appear" to fluoresce. VHOs with thier lower amounts of visible light do a great job in exciting the greener colors found in corals and don't do as good a job with reds, oranges, & yellows. This has to do more with the type of pigmenting of the corals than with the bulb itself.

In nature the corals with the most fluorescent pigmentation in the red, orange and yellow range are going to your zoanthids and your LPS corals.
 
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wizzbane15

New member
<a href=showthread.php?s=&postid=9831621#post9831621 target=_blank>Originally posted</a> by Aquabucket
Here is some more info for you to take in.

When it comes to reef lighting many think VHOs provide the best light for fluorescence. VHOs are the closest bulbs to the black light range and have the least amount of visible light as opposed to other types of bulbs offered. The problem is when you go to this range it takes more energy to gain intensity and these bulbs can appear to be dimmer than others that radiate more visible light...........

whatever he said.
 
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