UV-A / Blacklight Tank Lighting in Shorter Wavelengths

[Charlie the Reefer]

Hey everyone,

This is a "cross-post" from a general discussion thread - got zero traction there and it was suggested to post here.

I've been going down a lighting spectrum rabbit hole recently. Seems there's not really a consensus on ideal, holistic, spectrum to use.... And what intensities to have varying spectrums at (although lots of good info out there).

One sub-question in the lighting spectrum discussion I've been thinking about is regarding the shorter wavelength UV-A lighting spectrum (i.e. sub 380nm...). Yes, I know that UV light can be dangerous. I also know that there is not really robust evidence on whether UV light can facilitate the biological processes of coral/zoX in any meaningful way. And that UV light from the sun is filtered out in the ocean in substantially shallower water than blue. I also know that many LEDs are marketed as UV but are actually technically Violet or do not include substantial UV light.

That said, LED technology has progressed in a palpable way. I know that functional UV-A LED lights in these spectrums are available and have seen them. Additionally, MH bulbs as I understand it emitted substantial UV-A lighting that is potentially not matched by current LEDs (although there were fixtures to mitigate the extent of this emission).

Long story short - It seems the popular LEDs on the market only go as low as ~395nm. Why is it that we are stopping there? Can you get better fluorescence / colors by having even shorter wavelength UV lighting?

Has anyone tried sticking 365 nm LED lights above acros and seeing what happens?
Appreciate any discussion. Thanks.

 

[Charlie the Reefer]

As a follow up to the above... I bought a (true) 365nm flashlight off of Amazon. Very cool toy first of all. The lighting has next to zero visibility, save for objects that fluoresce from it.

Second, I used the 365nm flashlight on the corals at night, and I saw ridiculous colors I never even knew were possible in these corals. Only makes me wonder what are the possibilities of blasting these things with UV.... Mad scientist part of me I guess.

 

[oreo54]

Hey everyone,

This is a "cross-post" from a general discussion thread - got zero traction there and it was suggested to post here.

I've been going down a lighting spectrum rabbit hole recently. Seems there's not really a consensus on ideal, holistic, spectrum to use.... And what intensities to have varying spectrums at (although lots of good info out there).

One sub-question in the lighting spectrum discussion I've been thinking about is regarding the shorter wavelength UV-A lighting spectrum (i.e. sub 380nm...). Yes, I know that UV light can be dangerous. I also know that there is not really robust evidence on whether UV light can facilitate the biological processes of coral/zoX in any meaningful way. And that UV light from the sun is filtered out in the ocean in substantially shallower water than blue. I also know that many LEDs are marketed as UV but are actually technically Violet or do not include substantial UV light.

That said, LED technology has progressed in a palpable way. I know that functional UV-A LED lights in these spectrums are available and have seen them. Additionally, MH bulbs as I understand it emitted substantial UV-A lighting that is potentially not matched by current LEDs (although there were fixtures to mitigate the extent of this emission).

Long story short - It seems the popular LEDs on the market only go as low as ~395nm. Why is it that we are stopping there? Can you get better fluorescence / colors by having even shorter wavelength UV lighting?

Has anyone tried sticking 365 nm LED lights above acros and seeing what happens?
Appreciate any discussion. Thanks.

The " practical" reason is the stability issue as you go lower in the UV range.
Not too long ago you would go from say white/ blue diodes with a 50000hr lifespan to say a 365nm diode with a 5000hr lifespan
A 365nm at StevesLED.

Model Number -CUN66A1G

- Temperature - Can function up to 85°C or 185°F

- Lifespan - Rated at 1,000 hours minimum, although we have been testing them for more than a year and have some running for more than 5,000 hours now.

Keep in mind this is more photon output decreases not complete failure.
Depending on the test this could just denote a 30% decrease in output at 5000hrs.
In nature there has been some reported benefits for some UV.
Note though generally the stressors shouldn't be common in a home aquarium

Low levels of ultra-violet radiation mitigate the deleterious effects of nitrate and thermal stress on coral photosynthesis

Reef ecosystems are under increasing pressure from global and local stressors. Rising seawater temperature and high ultraviolet radiation (UVR) levels…

www.sciencedirect.com

 

[Charlie the Reefer]

The " practical" reason is the stability issue as you go lower in the UV range.
Not too long ago you would go from say white/ blue diodes with a 50000hr lifespan to say a 365nm diode with a 5000hr lifespan
A 365nm st StevesLED.


Keep in mind this is more photon output decreases not complete failure.
Depending on the test this could just denote a 30% decrease in output at 5000hrs.
In nature the gas been some reported benefits for some UV.
Note though generally the stressors shouldn't be common in a home aquarium

Low levels of ultra-violet radiation mitigate the deleterious effects of nitrate and thermal stress on coral photosynthesis

Reef ecosystems are under increasing pressure from global and local stressors. Rising seawater temperature and high ultraviolet radiation (UVR) levels…

www.sciencedirect.com

Interesting. I wonder if there is technological improvements possible to increase practicality of those lower wavelength UV LEDs.

Really, if you have SPS try one of those 365 nm flashlights on it at night. I have a purple montipora that looks super saiyan....

I can only imagine if you managed to fit an LED bar above your tank that emitted only UV spectrum in that range. Would probably look incredible (IMO).

I'll try to take some pictures later.

 

[JaimeAdams]

I'm here for the pics

 

[Charlie the Reefer]

I'm here for the pics

Hey Jaime - thank you for your interest.

First, disclaimer. I'm def still working on the photography skills. These pics are very amateur lol.

Second, these are all shot with an Iphone at night, no light filter was used. There is also no photo editing/filters, raw photos, and pretty good representation of what you see.

Only photo with a filter is the purple hammer comparison photo.

Purple hammer (day)

same purple hammer (365nm UV flashlight at night)

JF Fox flame!

Purple stag

Random corals on frag rack

 

[strich]

@Charlie the Reefer did you ever take this any further?

 

[Charlie the Reefer]

@Charlie the Reefer did you ever take this any further?

Thanks for the interest. I did, but only slightly further. I’m still very interested in this concept and feel it has room to be explored more.

I found a company that sells 365nm led strip lights. Waveform Lighting. I bought a 16.4 ft strip and adhered it to my 2x AI blade glows.

From what I can tell, these lights are doing next to nothing unfortunately. It seems the power is just not there. However, when all the lights are off and only these UV lights are on, there is kind of a cool fluorescence effect. I’ll try to take a pic.

Bottom line, it seems you really only notice the UV light effect when you take the flashlight and shine it directly on the acro. I am very curious if a more powerful UV dominant light fixture is possible down the line, and what its effects may be.

Again thx for the interest!

 

[strich]

My main curiosity is if given the same wattage can you get better fluorescence than blue light, which would be nice.

 

[JNalley]

Thanks for the interest. I did, but only slightly further. I’m still very interested in this concept and feel it has room to be explored more.

I found a company that sells 365nm led strip lights. Waveform Lighting. I bought a 16.4 ft strip and adhered it to my 2x AI blade glows.

From what I can tell, these lights are doing next to nothing unfortunately. It seems the power is just not there. However, when all the lights are off and only these UV lights are on, there is kind of a cool fluorescence effect. I’ll try to take a pic.

Bottom line, it seems you really only notice the UV light effect when you take the flashlight and shine it directly on the acro. I am very curious if a more powerful UV dominant light fixture is possible down the line, and what its effects may be.

Again thx for the interest!

Powerful UV Light fixtures already exist in the form of T5/T8/T10/T12 ballasts and bulbs, why not pick up one of those? They are typically 365nm peak (Often marketed as Blaclight Blue Bulbs), and they're relatively cheap when you're not paying the reeftank tax. Pretty sure you could get close to 50 watts with a decent ballast and bulb for around 50 bucks, certainly below $100. That should be more than enough power for your needs here...