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

[damsels are not mean]

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.

Clams in the wild also get a lot more food I imagine. They might survive in places they wouldn't in our tank due to the extra nutrition a wild reef can provide them. Maybe they need more light in captivity as a result?

 

[JNalley]

So, I am pretty sure I am going to pull the trigger on a Mitras LX 7206, I am going to run the 385nm chips on it at 100%, and I'll slowly add some of the 12W strips that @J1a has added if they will be so kind as to share a link for them. I will continue to add them slowly over time until I start to see negative impact and then dial them back. I also think I might try a UVB light from a reptile tank if I can figure out how to focus it on a single coral. I am pretty leary of UVB, but am willing to give it a go on a single cheap photosynthetic coral.

I really wish I had the money to conduct a long-term experiment on 2 identical tanks all with exactly the same corals trimmed from the same mother colonies at the same time and around the same size. I'd love to document that process, but that's so much money :-D

 

[J1a]

@JNalley I'll pm you regarding the light strips.

 

[ilikebeef]

yeh, I dunno, I went here: https://reefbreeders.com/product-category/lumenbar-color/ and didn't see anything labeled V2, so I just copied what was from those. Whether they're 380 or 385 those are the only ones below 400 which makes them the only True UV's. It's also hard to gauge how many there are per strip since they don't give that info (would have to buy them to count)... GHL employs 1 385nm chip per puck, and on the 7204's there are 4 pucks, and the 7206's have 6. I'm trying to map out how many LED's in True UV each one employs as well as a part of my data.

Link of layout from Reefbreeders https://www.dropbox.com/s/grm2ej07zv0npip/2020-5-16 LumenBar Color Layout.xlsx?dl=0

 

[J1a]

One more update, same phone camera shooting using manual mode with same settings, same yellow filter to cut down the blue light. With and without UV.

Some difference in color can be observed.

 

[Saltydog69]

Well I'm adding 2 uv light bars to my limited spectrum, with 1 I can tell you hammers are all loving it. BTAs need more acclimation but still loving it

what uv bars did you add? and where can i purchase one before i go all out and switch to mh lighting

 

[outhouse]

what uv bars did you add? and where can i purchase one before i go all out and switch to mh lighting

Reefbreeders luminbar at BRS. Corals love them and the visual pop is there with branching hammers. Not sure it helps over blue leds, but I enjoy the color change, and that's the reason I did such. I bought 2 60" for my 210g

 

[MartinM]

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.

I will say that my clams have changed color under higher intensity light, becoming ‘more colorful’. This has also happened on the same clam, where part of it was being shaded. But I also think there is refraction occurring, often both in the same animal.

 

[outhouse]

A few weeks with more UV and the coral looks better. Could be just added light alltogether more than spectrum. But the hammers really perk up to UV

 

[RMS18]

Go to 1:03:00



Not trying to put anybody out there. This was a public live stream so figured I’d post it so folks can understand what I’m referencing. I like Chris Meckley and I think he talks about a lot of interesting stuff at the farm and I enjoy listening to him. I just want to know if he or somebody close to him is on to something here, because I’m not a lighting expert. Maybe Dana Riddle can weigh in or you other lighting guru’s.

It was a good stream, I watched it live. I'm not an expert but I did hug my t5's afterwards and said thank you, you guys are doing a great job.

 

[Reefahholic]

I’m still not sold yet! Prove me wrong! I think EcoTech Radions have enough UV or UV isn’t needed. Too many nice longterm tanks with them running.

 

[J1a]

I’m still not sold yet! Prove me wrong! I think EcoTech Radions have enough UV or UV isn’t needed. Too many nice longterm tanks with them running.

I guess the question is if those nice tanks can be even nicer.

Radions have 405nm led as their UV diodes. While the spectrum will spread over somewhat into the UV region, I doubt there will be anything under 390nm.

 

[Reefahholic]

I guess the question is if those nice tanks can be even nicer.

Radions have 405nm led as their UV diodes. While the spectrum will spread over somewhat into the UV region, I doubt there will be anything under 390nm.

Probably not needed. I am really fascinated every time I see corals gown under metal halides. They either like the more daylight spectrum or the UV is really growing corals better.

What do you suggest I add for a little UV pop?

 

[J1a]

You have a very good point.

Based on what I have so far (a orphek OR3 with 380nm diodes) as supplement. I would say UV encouraged the coral to produce certain fluorescent pigments.

The red fluorescence was absent/weak until I added the UV light in the mix. This photo is taken with the UV light off. So the proteins continue to florescent under actinic light. To me, this is good.

It's not just a visual thing. It's a physical difference in coral biology.

 

[Reefahholic]

You have a very good point.

Based on what I have so far (a orphek OR3 with 380nm diodes) as supplement. I would say UV encouraged the coral to produce certain fluorescent pigments.

The red fluorescence was absent/weak until I added the UV light in the mix. This photo is taken with the UV light off. So the proteins continue to florescent under actinic light. To me, this is good.

It's not just a visual thing. It's a physical difference in coral biology.

Very nice!

 

[hart24601]

I still encourage anyone concerned about this to look at the photos from thermans reef. Just scroll though a few pages and look at his colonies . He uses mostly reefbreeders that only have 420 violets. No UV. If you can grow corals like his and decide you want to attempt even better, then perhaps worry about uv, but he shows what is possible without. If you can’t grow colonies as nice as his then the issue isn’t UV but something else like chemistry.

therman's 12 year old SPS system...top down shot, starting to enjoy this tank again

Hey Tim. How are you doing Great! How's the tank doing?

www.reef2reef.com

 

[damsels are not mean]

Maybe UV makes them look "nicer" but what's that? What is more color? Without being able to quantify the color change and be able to understand the effect UV has you are chasing a somewhat ambiguous goal.

You don't like what color they are already? What if you take a colony you bought because you needed some green in the top right corner and then took the advice that UV causes it to produce more fluorescence and it turned red?

Does this even matter to 99% of people in the hobby let alone this forum? Is lighting really the limiting factor in peoples' tanks?

I also think this is difficult to test and anecdotes really don't work because there are so many variables, and so much subjectivity. Without color-corrected before and after photos we can't really say if there is much effect on how colorful something is, because the slight change in intensity and spectrum would have an immediate effect on how we perceive the color. The added intensity also might intensify the color no differently than it would have if you added more royal blue or just white to the spectrum. Did your corals grow faster with UV or did the lights you used to provide LED add more heat to the tank that increased the calcification rate?

 

[J1a]

Does this even matter to 99% of people in the hobby let alone this forum? Is lighting really the limiting factor in peoples' tanks?

I may have to disagree with the first statement, while completely agreeing with the second.

This is why: if UV (or anyother factors) indeed contribute positively to the coral health or color, then it is useful for reefers. Who knows, maybe the big brand manufacturers will start to add them into their lights, this will have relevance to many reefers. While there are many papers describing the effect of UV on coral physiology, the only way to know if there is any impact, is for us to try it out. Unfortunately, at hobbyists level, we don't have access to multiple setups for controlled experiments, or chlorophyll fluorometer for quantifying photosynthesis. Therefore results tends to be anecdotal - which is really not ideal.

Lighting (UV specifically) is probably not the biggest issue a tank may face. Perhaps not even top ten issues. However there is really no harm to try things out.

 

[J1a]

You don't like what color they are already? What if you take a colony you bought because you needed some green in the top right corner and then took the advice that UV causes it to produce more fluorescence and it turned red?

Not to mention the color change may goes differently for different colonies. Such a complex issue.

 

[jda]

I do believe that lighting it by-far the most important thing in this hobby and does limit more people than they think. It is the only thing that actually feeds (gives energy) most corals. I would gladly take so-so stability and parameters and best-of-breed light over so-so light and best possible parameters.

Who doesn't want the best color? If they didn't black light, colorful fish and all of that would not happen. People would be happy with their semi-good-looking corals and not have to blue them up.