LED’s- No UV? Do corals need UV for longterm health?

[outhouse]

What can’t LED manufacturers make LED’s that duplicate the Metal Halide spectrum and have a good amount of UV.

Why is this hard to do?

the intense burning inside the MH replicates the sun burning closer. LEDs are a very small and very specific spectrum burning at a much lower intensity. UV might be part of it, mine love light under 420, not sure what combination of colors would help.

 

[J1a]

Some observations to report

I turned on the UV light strip (1:1, 365 and 380nm) after the dt light goes completely dark to see which fluorescence is activated. My observation is as follows.

It activates the fluorescence in my red stag, which the blue spectrum has not produce any fluorescence.

It produce a turquoise fluorescence which I have never observed in my tank. It's extremely bright.

It produce very strong orange fluorescence in my scolys, way higher than the blue spectrum.


You can also see from the pictures that the water is glowy, possibly due to very high organics. Also, the coral looks brighter than the photo.



So, if UVA is activating these fluorescence, then it would mean that the lack of sufficient intensity of UV will results in these fluorescence not visible. Thoughts?

 

[JNalley]

So, if UVA is activating these fluorescence, then it would mean that the lack of sufficient intensity of UV will results in these fluorescence not visible. Thoughts?

First thought: Thanks for sharing that's awesome it's bringing out more and different colors.

Light is a really funny thing, and you can take this with a grain of salt, but I read a paper/article where it claimed that everyone on the planet has brown eyes, there are no pigments of blue, green, etc that exist, but that the structure of the iris bends the light in such a way that was is reflected back are the various colors we see. It makes me wonder if something similar occurs with coral fluorescence (or fluorescence in general).

But I would agree that without sufficient intensity of the input spectrum, the other spectrums of light may drown out the visible fluorescence (If that's what you're stating). Have you tried with the strip AND the Blue/regular lighting together? Are the colors still present?

 

[J1a]

But I would agree that without sufficient intensity of the input spectrum, the other spectrums of light may drown out the visible fluorescence (If that's what you're stating). Have you tried with the strip AND the Blue/regular lighting together? Are the colors still present?

Not with this light for sure. This UV strip light is only like 12w. So even when it's turn on to maximum brightness, It cannot hold candle to regular/blue light.

While I believe those fluorescence are produced, they are drown out by the other spectrums. Would be interneting to see what a meaningful intensity will do.

 

[JNalley]

While I believe those fluorescence are produced, they are drown out by the other spectrums. Would be interneting to see what a meaningful intensity will do.

Well, as has been noted, UV rays can be harmful to living organisms and mess with DNA. So I think the best thing to do is actually start off low like you have, and slowly ramp up over time to see where the tipping point is, since this is uncharted (more like undocumented) waters.

 

[outhouse]

. So even when it's turn on to maximum brightness, It cannot hold candle to regular/blue light.

One would think that. When mine is ramping down the tank looks very dark. The visible light is just not there.

Do yourself a favor look at that light through your phone, there is a lot of light your phone will see you cant

 

[Dana Riddle]

@Dana Riddle you talked about photo inhibition under over-illuminated conditions. Would these conditions lead to more production of florescent proteins as a coping mechanism? If so, that will be fairly desirable.

A second question which bugs me for a long time: What is the best way to reconcile the lighting needs of acroporas and clams? Clams in general accepts very high Par before photos inhibition even sets in, yet they are often placed near the sand bed due to size etc. Is there a better way to cope with this?

If a colorful protein is made in response to light intensity (not all are), my observations suggest their production is triggered around the photosaturation point Usually 250-400 PPFD. Their purpose has been ascribed to them acting as photoprotectants due to wavelength transformation, anti-oxidant capability, etc. As for some of the deeper water or those living in light-limited environments, the fluorescence could act as an aid to photosynthesis. As for comparing lighting needs of Acropora and some Tridacna species, we need to consider several things. First is the light tolerance of symbiotic zooxanthellae type/clade/species. Of the 6 references I have for zoox found in Tridacna species, it is invariably Clade A (generally tolerant of high light). Acropora species usually (not always) contain a Clade 'C' type, which are highly adaptable to light intensity, thus making them tolerant of lower light. Another consideration: Tridacna mantles can get rather thick, and self-shading of zoox could actually require higher light in order to penetrate the thick tissue. On the other hand, Acropora tissues are generally razor-thin, where self-shading is less likely. A third possibility - Tridacna colors are due to refraction and not pigment content - it is trip to the eye - we see a color that isn't actually there. This is often seen in shiny, metallic appearing insects. However, the effects on photosynthesis are known (at least to me). Hope this answers your questions - if not, give me a shout.

 

[J1a]

One would think that. When mine is ramping down the tank looks very dark. The visible light is just not there.

Do yourself a favor look at that light through your phone, there is a lot of light your phone will see you cant

Oh, the intensity of those lights are measured with a spectral photometer. The intensity is really low. You can take a look at this.

I have temporarily rigged a 12w UV light strip over my aquarium. it's 1:1 ratio of 365nm and 380nm diodes

Seems like it does give a small bump in the UV region, but surely not very significant.

Let's see what this will do/if this will do anything.

 

[J1a]

If a colorful protein is made in response to light intensity (not all are), my observations suggest their production is triggered around the photosaturation point Usually 250-400 PPFD. Their purpose has been ascribed to them acting as photoprotectants due to wavelength transformation, anti-oxidant capability, etc. As for some of the deeper water or those living in light-limited environments, the fluorescence could act as an aid to photosynthesis. As for comparing lighting needs of Acropora and some Tridacna species, we need to consider several things. First is the light tolerance of symbiotic zooxanthellae type/clade/species. Of the 6 references I have for zoox found in Tridacna species, it is invariably Clade A (generally tolerant of high light). Acropora species usually (not always) contain a Clade 'C' type, which are highly adaptable to light intensity, thus making them tolerant of lower light. Another consideration: Tridacna mantles can get rather thick, and self-shading of zoox could actually require higher light in order to penetrate the thick tissue. On the other hand, Acropora tissues are generally razor-thin, where self-shading is less likely. A third possibility - Tridacna colors are due to refraction and not pigment content - it is trip to the eye - we see a color that isn't actually there. This is often seen in shiny, metallic appearing insects. However, the effects on photosynthesis are known (at least to me). Hope this answers your questions - if not, give me a shout.

Thank you for the comprehensive outline of fluorescence as well as the physiology of acropora and tridacna.

My second question could have been phrased clearer though. It's more about application in the aquarium. The tridacna, like you suggested, requires more light vis-a-vis acropora. However, very often the clams are places at the bottom of the aquarium, where light intensity is generally lower. How to provide these clams as much light as possible, without burning out the acropora and other corals.

 

[jda]

You are going to need months to see if you developed any proteins with that UV light. I would do your exercise again in March, or so.

Clams can catch food to get energy in an actually significant manner. Acropora - not so much, especially in our tank. Even if they can catch some something, nobody has any idea if they get any energy from it in broad form for multiple species and the only semi-study that people like to reference is not even on acropora. If the acropora can catch bacteria in the slime coat, they can assimilate nearly all of the energy and building blocks and this does appear to happen in our tanks. Clams can also overproduce zoox and digest it with their more complex digestive systems. I keep both clams and acropora at higher PAR than some and they appear to grow in proportionate levels... again, bottom need is not the same as thriving.

 

[J1a]

You are going to need months to see if you developed any proteins with that UV light. I would do your exercise again in March, or so.

Clams can catch food to get energy in an actually significant manner. Acropora - not so much, especially in our tank. Even if they can catch some something, nobody has any idea if they get any energy from it in broad form for multiple species and the only semi-study that people like to reference is not even on acropora. If the acropora can catch bacteria in the slime coat, they can assimilate nearly all of the energy and building blocks and this does appear to happen in our tanks. Clams can also overproduce zoox and digest it with their more complex digestive systems. I keep both clams and acropora at higher PAR than some and they appear to grow in proportionate levels... again, bottom need is not the same as thriving.

Yes. Months sounds like a good timeline

 

[Dana Riddle]

Thank you for the comprehensive outline of fluorescence as well as the physiology of acropora and tridacna.

My second question could have been phrased clearer though. It's more about application in the aquarium. The tridacna, like you suggested, requires more light vis-a-vis acropora. However, very often the clams are places at the bottom of the aquarium, where light intensity is generally lower. How to provide these clams as much light as possible, without burning out the acropora and other corals.

I haven't seen any papers describing photo-compensation points of Tridacnas (although I haven't looked lately and they might be out there somewhere), so I can only estimate photosaturation (certainly greater than 1,500 PPFD) in many cases. This is the long way around of trying to describe the sweet spot for maintaining clams and Acropora successfully in close proximity. But I've clams and stonies together at light levels of ~400 PPFD. The clams (I think) are under-lighted while the Acroporas are at max photosynthesis. I got notes of light levels for clams in one of my notebooks. Let me dig that one out. And I don't mean to stay the obvious (but I will - LOL) - I've seen at least displays that were dedicated to only photosynthetic clams.

 

[Dana Riddle]

Oh, the intensity of those lights are measured with a spectral photometer. The intensity is really low. You can take a look at this.

That is really interesting. The Russians reported light intensity in radiometric units but these never meant much to me since I was reporting it as PPFD. Was it Zvalinski?? Another reference for me to find.

 

[J1a]

That is really interesting. The Russians reported light intensity in radiometric units but these never meant much to me since I was reporting it as PPFD. Was it Zvalinski?? Another reference for me to find.

The spectral photometer i am using is a Chinese-made unit. Guess they do follow of the Russian convention. Fortunately, it reports PPFD as well. It measures whole lot of data including DLI. It break down and measure the spectrum in 5nm bands.

 

[Dana Riddle]

The spectral photometer i am using is a Chinese-made unit. Guess they do follow of the Russian convention. Fortunately, it reports PPFD as well. It measures whole lot of data including DLI. It break down and measure the spectrum in 5nm bands.

I hope they're the same, since watts is a SI unit. Very interesting. I found that log book in the first 5 seconds in the library. That happens only once in a lifetime. I'm going to start a new thread on Tridacna and PAR.

 

[JNalley]

@J1a and @Dana Riddle after reading your convo back and forth, could you not simply put a focusing lens on a kessil and point it squarely at the clam from a distance closer than kessil has rated, take a par meter, and dial in intensity, to solve the problem of "clam getting less light than Acropora" ?

 

[J1a]

@J1a and @Dana Riddle after reading your convo back and forth, could you not simply put a focusing lens on a kessil and point it squarely at the clam from a distance closer than kessil has rated, take a par meter, and dial in intensity, to solve the problem of "clam getting less light than Acropora" ?

Yes. But then that will also mean dedicating one fairly powerful light just to light the clams.

While in the wild, they could take up the same, similar niche.

 

[JNalley]

Yes. But then that will also mean dedicating one fairly powerful light just to light the clams.

While in the wild, they could take up the same, similar niche.

Hmm, I mean, an A180 should be able to do the job, and it's not all that powerful nor expensive.

As far as the wild goes, do they thrive in the same areas as Acros? I know very little about T. Clams, but I assumed they grew in shallower waters than most of our Reefs. ie 20m or less while reefs are generally around the 30-35m deep mark.

 

[damsels are not mean]

Hmm, I mean, an A180 should be able to do the job, and it's not all that powerful nor expensive.

As far as the wild goes, do they thrive in the same areas as Acros? I know very little about T. Clams, but I assumed they grew in shallower waters than most of our Reefs. ie 20m or less while reefs are generally around the 30-35m deep mark.

Really depends on what corals you have. A lot of our tanks, even SPS dominant reefs, are a mix of corals from different depths. Most staghorns are found much deeper than millis for example. Here's some huge clams right in the middle of some porites, acros, etc.



Everything here seems pretty healthy. I do think clams like this are only found in very shallow waters, though, while corals are a bit more adaptable.

These videos are great because I don't dive, but it shows just how mixed each part of the reef is and gives some perspective. There is a point later when there's a huge happy hammer coral in water no deeper than a few feet. Likely gets exposed at low tide with the rest of the SPS. On the other hand, there are tabling acros and montis further out that you can't get to without an oxygen tank. Dive vids from the perspective of an aquarist give more attention to the corals than most dive vids which is why I like these ones. Thanks Jake.

 

[J1a]

Really depends on what corals you have. A lot of our tanks, even SPS dominant reefs, are a mix of corals from different depths. Most staghorns are found much deeper than millis for example. Here's some huge clams right in the middle of some porites, acros, etc.



Everything here seems pretty healthy. I do think clams like this are only found in very shallow waters, though, while corals are a bit more adaptable.

These videos are great because I don't dive, but it shows just how mixed each part of the reef is and gives some perspective. There is a point later when there's a huge happy hammer coral in water no deeper than a few feet. Likely gets exposed at low tide with the rest of the SPS. On the other hand, there are tabling acros and montis further out that you can't get to without an oxygen tank. Dive vids from the perspective of an aquarist give more attention to the corals than most dive vids which is why I like these ones. Thanks Jake.

The other thing here to consider is the survival bias. For one or a few clams which have settled in a particular environment, how many more has tried, and failed.