Experiments with UV Light on Tank [NOT UV sterilizer]

[ReeferBatman]

Is anyone out there experimenting with UV light?
I have done so briefly for the colors/aesthetics… but I came across a $30 -4 foot- T8 – 36 watt Black light at a Halloween store the other day.

4 Feet long? Perfect for my 55!

And at 30 bucks, it would certainly be the cheapest aquarium ‘experiment’ to date lol…

Long story short, I jerry-rigged the blacklight into my multiple fixture canopy… and then added another smaller 2 foot but stronger (t5) blacklight to accent certain corals… and put them both on my Timer system to go on for 1 hr before any other lights come on, and after they go off (only staying on for that 1 hour).

UV has several characteristics to consider. The lower the nm of the UV light, the more biological damage it inflicts upon the cells…
UVA is 320-400 nm
UVB is 290-320 nm
UVC is 100-290 nm (and is the most destructive to cells)

Light in the UV spectrum is invisible to our eye, the light we “see” from the blacklight itself is diffused UV radiation leaking out at the mostly 400-415 nm wavelengths.

The fact that Corals are exposed to UV-A light even deep as 60 feet, and some pigments do in fact use UV A light to fluoresce has me thinking and experimenting now.

The Blue and Violet fluorescing Pociloporin pigments use UV light [Violet = 310-380nm light to fluoresce a blue btwn 400-470nm / Blue =380 into the 400’s to fluoresce a blue/green btwen 476-520nm),

Some of the more specific Pigments that utilize UV-A light are…
P-445 (Excitation ~340nm)
P-400 (Excitation ~345nm)
P-486 (Excitation ~384nm)
P-509 (Excitation ~397nm)
P-496 (Excitation ~399nm)
P-446 (Excitation ~380nm)
P-440 (Excitation ~358nm)
P-486 (Excitation ~384nm)

Their emission spectrum is their name… so P-486 “eats” 384nm light, and “spits out” 486 nm light. Compare that to the nm Spectrum and you have your emission color.

Ref for those specific pigments:
http://www.advancedaquarist.com/2006/9/aafeature


So several coral pigments are known to use UV light.

Other corals that are exposed to high amounts of UV light [over the evolutionary life-span of the species not the individual] also have developed photo-conversion to screen out excess UV light, and in result fluoresce amazing Yellows and Oranges.

Photoconversion - the rearrangement of a chromophore by light energy resulting in shifts in perceived coloration - is known to occur in quite a number of green fluorescent pigments.

Photoconversion of GFPs to Kaede Pigments

Nature loves to confound us, and the conversion by light energy of one pigment to one of a different fluorescent emission certainly falls into this category. Photoconversion can occur in many pigments but is most well documented in those pigments classified as Kaede pigments. These are found mostly in suborder Faviina (which includes about 60 stony coral genera, including Catalaphyllia, Favia, Lobophyllia, Montastraea, Mycedium,Trachyphyllia and others), but also occurs in some soft corals (Dendronephthya sp.), and false corals(Ricordea).

The photoconversion from green to orange/red Kaede pigments requires blue light (see Table 2).

Table 2. Photoconversion: Green Fluorescent Proteins convert to orange Kaede pigments (Clade D) upon exposure to ultraviolet/violet/blue light.
From To Host Clade/Pigment Activator
P-505 508/572 Montastraea cavernosa D ? - But most likely blue light
P-505 506/566 Ricordea florida D ? - But most likely blue light
P-508 575 Dendronephthya sp. D Blue Light @ 488nm
P-508 575 Dendronephthya sp. D UV-A at 366nm
~516 582 Montastraea cavernosa D Depth- light -related?
P-516 581 Lobophyllia hemprichii D UV @ 390nm/Violet Light ~400nm
P-517 574 Ricordea florida D UV/Violet Light
P-517 580 Montastraea annularis D UV/Violet Light
P-517 593 Favia favus D UV & Violet (350-420nm)
P-518 582 Trachyphyllia geoffroyi D UV - Violet Light (350-410nm)
P-519 580 Montastraea cavernosa D UV - Violet Light

Ref: http://www.advancedaquarist.com/2009/2/aafeature1



So we know some corals do use the upper registers of UV light to fluoresce and/or “produce photosynthetic food” for the coral.

The Phosphors typically used in “human use” [T8/T5] Blacklights (different than “industrial use, possibly UV-B blacklights) peak around 350-353nm (lead-doped barium silicate ) or 368-371nm (europium-doped strontium fluoroborate / europium-doped strontium borate),

So in all likely hood, those are my peak spectrums delivered by my 2 UV blacklights.

I also use a glass top, which I’ve read screens out a lot of UV light… food for thought…

Time to experiment!

The other lights I have give off very little UV light, and it is ‘outcompeted’ by fluorescing colors of the upper nm spectrums…
so isolating the UV light helps isolate and activate certain pigments.

Example: Here is my Favia under LED blue Light (peak ~450nm) and under my UV Blacklights(~350-370nm)

Notice the intense different fluorescence activated by the UV spectrum on that Prizm Favia, including those awesome yellows/oranges made by those "Kaede pigments"?


My only worry is that although some corals evolved to handle increased UV exposure (like that Favia), Other corals have not evolved “blocker pigments” to prevent that UV from damaging the DNA/RNA of the corals cells -> Leading to degradation of cells and quality of life for that coral.

IE. Some corals do well and might even thrive better, but others could potentially do worse at the same time…

So I’m trying to find a balance with time vs exposure to the UV A Light. Right now, I’m going for “on then off 1hr” at beginning / end of day…
1 hour blacklights (then off)
1 Hour LED “Actinics” ~450 nm (stay on all day)
9 Hour 110w T5 [1x Actinic / 1x ATI Blue Plus]
7 Hour 110w T5 [2x 10k]

All on timers so that my tank “ramps up” and “tapers down” in the following manner…

UV Only

LED Blues Only

LED + T5 Blues

LED + T5 blues +T5 whites

So… Anyone else experimented with UV?

Right now, the UV lights are on for 1 hour before and after all the other lights.

I guess I will document my findings here and see how they do over the next two weeks…

 

[jtmbtech]

I know there are multiple people using UV leds so let us know how it works out. I for one am berry curios to see!

Sent from my cm_tenderloin using Tapatalk 2

 

[ReeferBatman]

Humans can't see UV, and until fairly recently we thought UV light was virtually absent below the waves. We now know that UV can penetrate to depths beyond 300 feet, and that some fish not only see UV but also paint their bodies with UV reflectors to beam out messages to their kin. Damselfish, for instance, shout out to each other in UV, but their predators can't see it.

http://ngm.nationalgeographic.com/ngm/0505/text2.html

In nature, UV rays are filtered out by ocean water. The deeper the water, the more UV rays are filtered out of the spectrum. Since corals produce these colorful pigments as a protection from the UV rays striking them, shallow water corals have more colors: More UV, more color; Less UV, less color.

http://saltaquarium.about.com/od/coralcare/a/whycoralschange.htm



Looks like Calcium carbonate corals have evolved to successfully block out excess UV pretty well...

http://www.asknature.org/strategy/5cf7bac29b9f3314f68058543259dff4

 

[Lionfish666]

I'm experimenting with a few UVA bulbs on my tank, arguably violet, sold to me as 400nm. I would say they are ultraviolet as I can barely see the light, just a glimmer of deep purple/violet, whilst the other 3 watt bulbs (neutral white, blue, royal blue) blind me.
My personal belief is that some of the failings people seem to be having is that most of the LED light emitted doesn't cover the lower wavelengths we know corals use, around 400nm, while in comparison halides (despite there UV shields) and to a lesser extent T5s, do put out radiation in these wavelengths ie 350-400, and it doesn't seem to harm peoples tanks. It explains why people have such success with LED supplemented with halides or T5. I would think if you get balance right UV leds would be a good thing, being a reflection of the light corals are used to, but too much is undoubtably harmful. I'll post up some pics on the weekend and we can see how they progress, but be warned I have a lot of trouble getting decent photos.

 

[ReeferBatman]

I recently read Dana Riddle's UV article on how it was not useful...

Although I usually regard his articles as very well written and scientifically based...

His UV article was based upon observations of only 1 type of coral, that he said himself grows better lower on the reef, and is smaller and less robust near the surface.

This tells me that the majority of that coral species evolved lower on the reef, and although it might survive higher on the reef, it outside of it's "comfort zone" of UV exposure when high on the reef.

That said, other coral's (like some SPS and favia it seems) have evolved with the more intense UV in mind...



It's really a crap-shoot it seems, some corals will do well, color up and might use the UV radiation, but other corals might not be able to handle it...

Even if it doesn't result in biological damage, it still might result in Photo-inhibition [reduced productivity of photosynthetic pigments] in some corals not typically exposed to the light...



Another Factor I'm thinking about is the fact that I only have the UV light on for 1 hour before/after all the other lights, when in reality the corals receive UV all day...

I wonder if there is another interplay between UV and higher light...

IE... I wonder if the corals cannot fully use the UV spectrum when the higher spectrum is absent... I know at least one UV pigment has a 'relationship' with higher nm peaks as well...


I guess only time will tell...

 

[Lionfish666]

Well the UV lights have been on for 3 months now, all day, the SPS have super colour but the LPS (torch on left) is looking pretty washed out.

How are your corals going Batman?

 

[ReeferBatman]

They are doing fine... but the UV experiment...

After I would say 2-3 weeks I noticed little effect in most corals, an increase in coloration and growth from some corals; my Favia and Favites, But a decline in coloration and generally less happy $300 Open Brain Coral...

And that one Coral was enough to halt the experiment for me.

Some did better, some did worse, most were visibly no better off either way...

So I decided the 'risks' outweigh the benefits for everyday intense use in my tank...

But I still keep the UV's around for occasional extra awesome night-time viewing...

The colors that come out in the favia = AMAZING!

 

[ReeferBatman]

double-post