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

[ineption]

What a great conversation!
Call me crazy I will probably come across as smarty pants, but I feel this need to be pointed out :
One thing that no one has mentioned is that Chris from ACI did say the torch coral that he had moved to LEDs was in completely different system and that system was quiet new in comparison to his main system which had MH over!
Also worth noting that it takes time for corals to adjust to a different system like few months.

I talk from personal experience where I have 2 frags of identical coral being placed in different positions in the tank and one dies the other thrives.
Had Chris placed leds over his main system where torches had been accustomed to being and they closed up considering the corals was within decent par range then it would be something to take in to account.

My take on this is I recon there must be a reason why a lot of reefers seem to say that MH grow corals faster, looking at spectrum charts and it's evident that its quiet broad I.e starts at 360 nm all the way to 700 s ir range.

Few members pointed out that we aren't sure on exactly how uva, uvb, uvc interacts within whole reef ecosystem I.e does it kill certain harmful bacteria ect (not known yet it seems)

I would personally say it would be ideal to mimic the actual spectrum corals receive in the ocean and from what graphs I have seen I can see a small bump on 380 so there must be something to it.

On the other hand to play devil's advocate sort of speak. I have seen some incredible tanks with Radions and Reefbreeders only which some members have pointed out which do not have UV.

Man this hobby makes me feel stupid at times and also so confused lol. This is called cognitive dissonance.

The conversation and test should continue so we can arrive at a point which is more likely then unlikely...

 

[JNalley]

That test is so flawed that it should be disregarded. I one performs the same test dry, and in many cases, you'll see the same drift (dynamic spectrum). More often than not, the spectrometer is seeing the PWM dimming of different channels. The colors are simply cycling at different frequencies. I've tested the same lights with the same spectrometer.

Sure, but I wasn't discussing the validity of the test or their methods. Just that "It needs to be done under water" and that test is obviously done, under water...

 

[JNalley]

Not a well actually, but there are others I've personally measured, like the Red Sea 90, that have UV. In this case, a 385nm bump. I mentioned GHL and Kessil because I know they appropriately advertise UV.

Hehe, sorry if you feel I misquoted you, it wasn't my intent, I wasn't going to scrub the video for the comment, I just could have sworn you said "the only two I know of are...". So I assumed, that maybe at that time, you had only known of those two. My intention was to say, that there are more than 2 that include and advertise true UV LEDs. I have been looking at LED layouts of the various lighting companies to try and see who has UV and who doesn't and compiling a list for my own personal data. I for one feel like UV is important if our end game is to recreate the sun for a marine environment.

 

[telegraham]

Sure, but I wasn't discussing the validity of the test or their methods. Just that "It needs to be done under water" and that test is obviously done, under water...

Totally get where you're coming from. From my perspective, the data suggests it's a test created to sell lights. To differentiate "good" from "bad." In application, it's irrelevant.

 

[telegraham]

Hehe, sorry if you feel I misquoted you, it wasn't my intent, I wasn't going to scrub the video for the comment, I just could have sworn you said "the only two I know of are...". So I assumed, that maybe at that time, you had only known of those two. My intention was to say, that there are more than 2 that include and advertise true UV LEDs. I have been looking at LED layouts of the various lighting companies to try and see who has UV and who doesn't and compiling a list for my own personal data. I for one feel like UV is important if our end game is to recreate the sun for a marine environment.

...and I like your data! Appreciate the effort and clarity. Lots of misleading data out there.

 

[Reefahholic]

One more low light tank. This is from a guy in our group (Oscar Vascos).

Only 4x T5’s
And…2x Orphek LED Bar “knockoffs” from AliExpress.


Makes you question…do SPS really need 400-600 PAR? Keep in mind…this only 6 months between photos. I’d say that’s pretty decent growth for 4 T5’s and some knockoff LED bars.

 

[telegraham]

One more low light tank. This is from a guy in our group (Oscar Vascos).

Only 4x T5’s
And…2x Orphek LED Bar “knockoffs” from AliExpress.


Makes you question…do SPS really need 400-600 PAR? Keep in mind…this only 6 months between photos. I’d say that’s pretty decent growth for 4 T5’s and some knockoff LED bars.

Love me some populargrow bars. $45 for 24" 470nm or $60 for a custom spectrum.

 

[damsels are not mean]

One more low light tank. This is from a guy in our group (Oscar Vascos).

Only 4x T5’s
And…2x Orphek LED Bar “knockoffs” from AliExpress.


Makes you question…do SPS really need 400-600 PAR? Keep in mind…this only 6 months between photos. I’d say that’s pretty decent growth for 4 T5’s and some knockoff LED bars.

Corals certainly don't need 400-600 in fact growth for all photosynthetic corals peaks in the 100-200 par range. More light supposedly boosts color and that's all.

 

[Reefahholic]

Love me some populargrow bars. $45 for 24" 470nm or $60 for a custom spectrum.

Yeah, he said he called and got them to mimic the Blue+ spectrum.

The T5’s were…

In that pic of the lights I have:

ATI
2 blue plus
1 coral plus
1 aquablue special

Since that pic I changed to less blue with the T5s, because these LED bars produce a ton of blue and pop. Now I have:

2 coral plus
2 aquablue special

 

[Reefahholic]

Corals certainly don't need 400-600 in fact growth for all photosynthetic corals peaks in the 100-200 par range. More light supposedly boosts color and that's all.

Yeah, I see intense light producing great coloration, but there’s also been some good growth too. The growth is just different from what I like. So it’s really hard to pin down exactly how much light corals really need, because they seem to adapt to
everything.

I do notice that PAR under 300 seems to grow taller less compacted colonies while PAR north of 300 seems to grow more compact and shrub like shorter colonies with intense color.

The problem is we see people like Sanjay maxing his Radions at 100%, but he also runs with higher nutrients (or did for a while) so we want to turn our lights up.

Looking at Rico’s old 300DD tank I can tell you 100% that his PAR was under 300 especially at the bottom of the tank. He told me he kept that tank 100 on the sandbed and look at some of the corals down there.

So I have to run lower light in my new system to find out for myself. Thinking back…the best vertical growth I’ve ever had came from a 6 bulb ATI Sunpower fixture. When I got the 8 bulb ATI LED Powermodule module I only ran the LED’s at about 40%, but between the LED’s and the T5’s it was just too much light for the majority of the corals. I was dosing nutrients into the system, but the corals were still becoming pale at times especially at the top of the tank where the light was most intense. It was really cooking them. The rocks were constantly letting off air bubbles so I know it was hot. The corals I had at the bottom of the tank looked much healthier than those at the top of the rocks. The tissue and axial corallites also looked healthier. So that makes me want to revisit lower light to know for myself. For me it’s not all about color. It’s about healthy corals that grow tall and put out some nice branches. I’m never impressed when I see the short compacted colonies no matter how intense the colors are. I may be completely wrong, but looking at the corals below, I have to give it a try.

I doubt they sitting in anything more than about 200 PAR when we know that the sandbed was at 100 PAR.

 

[Reefahholic]

Corals certainly don't need 400-600 in fact growth for all photosynthetic corals peaks in the 100-200 par range. More light supposedly boosts color and that's all.

I always find Jake Adam’s pic interesting. I wonder if this thing was in deep water, because looking at the background it certainly doesn’t appear shallow.

This pic peaks my interest as well.

 

[Reefahholic]

You can see the difference with TSA colonies. They look amazing with the intense colors, but not how they’re compacted and short compared to the pic above.

Top Shelf Aquatics Teaser

youtube.com

 

[Hydrored]

For the life of me. I can't explain why Apogee doesn't advertise the ePAR sensor 'sees' radiation down to 380nm. I'll get in touch with Chris Madsen at Apogee and see what he has to say. I think Apogee is doing themselves a disservice.

I ordered the 610 and should be here any day, still not positive how it differs from the 510 for a reefer like me. My 510 has been on the fritz so I had to send it in for service, it was jumping 150 + par just sitting idle with zero flow so I don’t know with my new lighting if I have 300 or 450 + par. My guess is the later (not wanted)

 

[J1a]

Tangential to the discussion, but nevertheless interesting: a study suggests blue (455 nm) lights activates light enchanced calcification in some corals (through blue light receptors). It also show that photosynthesis is below saturation even at 400Par of blue spectrum.

Light Enhanced Calcification in Hermatypic Corals: New Insights from Light Spectral Responses

Light enhanced calcification (LEC) is a well-documented phenomenon in reef-building corals. The main mechanism proposed for LEC is that photosynthetic CO2 uptake by the algal symbionts elevates the pH and thus enhances calcification. We evaluated the role of light and of photosynthesis on...

www.frontiersin.org

Now this is very interesting.

 

[Aqua Man]

Color and growth aside, I’ve heard that even without UV that coral will spawn. So if they are spawning then they are healthy! I don’t remember which reefbum podcast that I heard it on though. Might be this one

Rappin' With ReefBum: Guests: Tullio Dellaquila from Reef Brite AND Rich & Ben from Reef Beef on Apple Podcasts

Show Rappin' With ReefBum, Ep Guests: Tullio Dellaquila from Reef Brite AND Rich & Ben from Reef Beef - Oct 5, 2021

podcasts.apple.com

 

[JNalley]

Color and growth aside, I’ve heard that even without UV that coral will spawn. So if they are spawning then they are healthy! I don’t remember which reefbum podcast that I heard it on though. Might be this one

Rappin' With ReefBum: Guests: Tullio Dellaquila from Reef Brite AND Rich & Ben from Reef Beef on Apple Podcasts

Show Rappin' With ReefBum, Ep Guests: Tullio Dellaquila from Reef Brite AND Rich & Ben from Reef Beef - Oct 5, 2021

podcasts.apple.com

Sure, but consider this for a moment. I am a healthy human being, however, I could be healthier, there are things that I miss out on (I don't drink enough water, nor do I get enough sunlight, and while I think my nearly carnivorous diet is good, others might argue and say it's not, also, I eat junk food from time to time. Just because I am healthy (per my physical every year) does not mean that I couldn't be healthier. We know a lot about human physiology and what the human body needs, we know far less about coral and what they need. What we are attempting to achieve is optimal conditions, we know those conditions exist in the wild because that is where they have thrived for millions of years. That environment contains UV Light, so even though they're healthy without it, UV may be tied to some other process we know almost nothing about but that could aid in the coral being healthier... Just food for thought...

 

[Randy Holmes-Farley]

What we are attempting to achieve is optimal conditions, we know those conditions exist in the wild because that is where they have thrived for millions of years. That environment contains UV Light, so even though they're healthy without it, UV may be tied to some other process we know almost nothing about but that could aid in the coral being healthier... Just food for thought...

As long as we are in the "may" zone, it may be unhealthier as well. Lots of natural things are very unhealthy. Many are lethal.

 

[JNalley]

As long as we are in the "may" zone, it may be unhealthier as well. Lots of natural things are very unhealthy. Many are lethal.

Completely agree, personally though, I think the best approach is baseline first (natural environment), experimentation second (calculated changes and deviations from the natural environment conditions to study and find optimal conditions). Since we have yet to achieve the natural environment baseline (in lighting(and have very little science on coral lighting specifics in general)), getting the baseline right first should be a priority. We already have this with saltwater and chemical parameters. Finding a way to get there with Lighting Spectrum should be our next step. Then from there, we can make calculated changes (as we have with Alkaline, Calcium, and Magnesium levels) to achieve the best environment possible for optimal coral growth and health under LED lighting schemes. That to me feels like the better approach than blindly shooting in the dark or giving them only what we know.

 

[Reefahholic]

Tangential to the discussion, but nevertheless interesting: a study suggests blue (455 nm) lights activates light enchanced calcification in some corals (through blue light receptors). It also show that photosynthesis is below saturation even at 400Par of blue spectrum.

Light Enhanced Calcification in Hermatypic Corals: New Insights from Light Spectral Responses

Light enhanced calcification (LEC) is a well-documented phenomenon in reef-building corals. The main mechanism proposed for LEC is that photosynthetic CO2 uptake by the algal symbionts elevates the pH and thus enhances calcification. We evaluated the role of light and of photosynthesis on...

www.frontiersin.org

Now this is very interesting.

I think that’s what @Dana Riddle was saying. I believe he said 400 which is where he was keeping his tank now during peak photo period.

 

[outhouse]

I can tell you my branching hammer all perk up in the morning with my black light. 385 and low 400,s. And fill out as much as when the blue lights come on. BTAs do a little but that is the same for blue. The white cones on and they all pick up.