Have we been wrong in our understanding of PAR this whole time??

[BeanAnimal]

Sorry, ignore the my first picture of the spectrum. This is the right one.

Exactly as I said, still a lot of blue there but the other spectra is cranked up and drowns it out visually. That has nothing to do with corals not “seeing” it.

 

[BeanAnimal]

As for JDA’s point. Yep, most of it comes from shallow easy to grab locations. That is what makes money.

 

[jda]

There is more blue in the sun, 3200k T5 light, plasma, 5500k Mh bulbs than in a Radion Gen 6 blue... they just have more of the other spectrum too.

I did not read through all of the pages, but did @Lasse show/mention you the studies and stuff that suggest that green light is able to penetrate tissue, layers and provide energy below the surfaces? Red is good for many things too.

 

[Lasse]

I did not read through all of the pages, but did @Lasse show/mention you the studies and stuff that suggest that green light is able to penetrate tissue, layers and provide energy below the surfaces? Red is good for many things too

I think I mentioned my leaf experiment................. But here is another link where I describe that experiment. I have use the penetration schema from open water as an example but even in swallow water (above 50 m) - there is a lot of green in the water

Sincerely Lasse

 

[areefer01]

Idk it grows coral, sry not playing semantics and I’m not going to site any studies sry just from my exp. So ab+ @ 100 % has proven to work for me.

Wasn't a challenge to you but rather asking for clarity. Working for you may, or may not, work for me. Or any hobbyist for that matter. Thus me tripping up over the "proven" choice of wording.

• Is it the type of light?
• Is it the spectrum?
• Is it the duration?
• Is it your experience?
• Is it luck?

So many variables.

 

[areefer01]

As for JDA’s point. Yep, most of it comes from shallow easy to grab locations. That is what makes money.

How much is wild vs aquaculture vs hobbyist trading these days. Not sure how much that factors in these days or into this discussion.

 

[Acroguy]

I bet if someone would compare a light with just blue spectrum and a full spectrum light to grow SPS the full spectrum would win hands down.

 

[Acroguy]

Exactly as I said, still a lot of blue there but the other spectra is cranked up and drowns it out visually. That has nothing to do with corals not “seeing” it.

No one said that corals are not seeing it.What Iam saying is that even though there is a peak in the blue spectrum, corals utilize the other wavelenghts as well.

 

[oreo54]

You might find this interesting..
quality_of_light

The corals from shallow water are clearly adapted
to full light spectra whereas deep corals are adapted to blue light
spectra. Thus, chromatic adaptation and, probably, the zooxanthellae
cladal differences provide selective advantages by maximizing
photon capture and photosynthetic activity under the different
spectral conditions that occur in the reefs of Eilat, Red Sea

 

[SashimiTurtle]

MANY, people have tried to explain PUR to hobbyists and vendors alike, and everyone jumps on the "I gotta have max PAR" lemming train like cultists.

 

[areefer01]

Just curious as to why we are not providing papers written by Dana on this subject. Has MACNA presentations and real-world studies of corals and light in oceanic conditions. Reef related.

 

[MnFish1]

I know, it's a discussion . Your point here is exactly what I'm implying needs to be done. We need to measure our par by only measuring the blue end of the spectrum (and possibly a very small amount of red, but that's debatable with how important blue is. I'm currently reading a study on red repression). Then if we leave the blues alone and add in the whites for our own visual pleasure we'll have a much more effective lighting set up.
For clarification this relates to LEDs more than other light sources. A 6500k metal halide will have all the blue necessary most likely, it just has a lot of the other wavelengths too. The par this gives out will be significantly high than day a 20000k MH I'd assume

I would suggest that 1 study, with 1 variety of coral should not cause a mass stampede to 'blue lights'

 

[PeterErc]

PAR, coral placement, used to be where in the tank did you have it? How were the colors up high compared to down low.

Now it’s what fixture are you using, what intensity, are you using diapers, rollers, controllers. What are you dosin? Did you see the new BRS video? OMG, did you see Jimmy’s tank? I am gonna try that!!

I like my lights, on/off no tinkering, if I don’t like it, change the bulb.

What about cloudy days, storms, sponge spawns or plankton blooms, seasons etc. etc etc… Maybe corals will do better under inconsistent spectrum, par, lux, flux capacitor. Heck if I know.

Way too many variables, I prefer to use proven lighting methods. So, So many new fixtures on the market, sure they work. It’s always an argument about which is better. Some like this look, and others don’t. If you and the animals are happy with your lights, good..

 

[Lasse]

Just curious as to why we are not providing papers written by Dana on this subject. Has MACNA presentations and real-world studies of corals and light in oceanic conditions. Reef related.

Fun your saying this - when I saw this thread I was debating with my self if I should answer with my own words or just provide two simple links like this

Search results for query: *

www.reef2reef.com

and

Search results for query: *

www.reef2reef.com

How much is wild vs aquaculture vs hobbyist trading these days. Not sure how much that factors in these days or into this discussion.

This is important because its known that corals can adapt to different light scenario and I remember a discussion I had with Dana in another thread (which I do not remember) that just short waved near UV light was the ones that triggered the formation of "sunscreen" pigment which protects the coral animal from free radicals and to evolve a too high photosynthesis. The red wavelengths seems not have the same "trigger" effect but cause a very high photosynthesis. If you look on both diagrams of light penetration you will see that UV disappear already at 5 m in coastal waters - faster than the read wavelengths

This source state that wavelengths around 400-430nm has been proved to be essential for the excitation of Blue Fluorescent Proteins and Cyan Fluorescent Proteins.

IMO - if you run full spectra in high PAR - you need to have wavelengths all down to 400 nm in order not to burn your corals and get vivid colours. IMO - UV (below 400 nm) is not needed of biological reasons as I know for today.

Sincerely Lasse

Sincerely Lasse

 

[Doctorgori]

A bit of history and semi rant might be relevant here:

This whole “blue light” thing came about in the 90’s when a certain VERY renowned and respected Doctorate/hobbyist did a study on coral photosynthesis which (to some people) proclaimed once and for all that blue light was all that was needed PERIOD.

…..and coincidentally about that same time Radium’s came out and suddenly windex “Blue” was in and Iwasaki 6500ks were OUT…

…you couldn’t argue with the name dropping minions and/or breach the pseudo relationships/allegiances within the culture of the old newsgroups and bulletin boards… flame wars ensued and the name dropping blue light supporters won the day.About the only way to stop a Radium lover was to pry the burnt out light bulbs from their dead hands…
- I honestly believe the entire picture of coral biology isn’t 100% understood, I don’t think the final answer on their biological needs is in
-I think lighting spectrum application/ logic is misapplied and white light gets a bad rap for algae
-I think the insane photoshopped candy colors that corals are sold under has contributed to blue light’s popularity and lighting misinformation …
- white light AlWAYS contains blue or rathe I have no clue how to get white without it

 

[BeanAnimal]

Yep before RC and R2R we had a Usenet group and from there you could get the link to the MUD that wasn’t a mud, but rather a reef chat. 6500k or die was the way.

 

[Troylee]

A bit of history and semi rant might be relevant here:

This whole “blue light” thing came about in the 90’s when a certain VERY renowned and respected Doctorate/hobbyist did a study on coral photosynthesis which (to some people) proclaimed once and for all that blue light was all that was needed PERIOD.

…..and coincidentally about that same time Radium’s came out and suddenly windex “Blue” was in and Iwasaki 6500ks were OUT…

…you couldn’t argue with the name dropping minions and/or breach the pseudo relationships/allegiances within the culture of the old newsgroups and bulletin boards… flame wars ensued and the name dropping blue light supporters won the day.About the only way to stop a Radium lover was to pry the burnt out light bulbs from their dead hands…
- I honestly believe the entire picture of coral biology isn’t 100% understood, I don’t think the final answer on their biological needs is in
-I think lighting spectrum application/ logic is misapplied and white light gets a bad rap for algae
-I think the insane photoshopped candy colors that corals are sold under has contributed to blue light’s popularity and lighting misinformation …
- white light AlWAYS contains blue or rathe I have no clue how to get white without it

It sounds like we should all just take a step back and talk to our corals and ask them what they truly want!

 

[Doctorgori]

the problem began when they discovered Radiums grew and showed off corals like a mutha… from then
on once the performance was proven, nostalgia set in and like Betamax lovers these old foggies won’t let MH die …

heck some of them still are mining junk yards and 2nd hand stores for bulbs and parts (you can tell a Radium addict by the fan noise they emit)

 

[Troylee]

the problem began when they discovered Radiums grew and showed off corals like a mutha… from then
on once the performance was proven, nostalgia set in and like Betamax lovers these old foggies won’t let MH die …

some of them still mining junk yards and 2nd hand stores for bulbs and parts (you can tell a Radium addict by the fan noise they emit)

I will use metal halides till I can’t find bulbs! I love them!

 

[oreo54]

Effects of LED Light Illumination on the Growth, Digestive
Enzymes, and Photoacclimation of Goniopora columna
in Captivity

At least
6 h per day LB or LP (400–470 nm) light and feeding will help growth, polyp extension,
protein composition, and protease activity. For aquaculture applications, shortening the
light time will reduce the cost of electricity. These are the optimal conditions for aquaculture
G. columna. In addition to being applicable to large-scale farming, our findings can
reduce the collection of wild corals and allow natural coral to achieve conservation and
repopulation. At present, the light exposure at the CITES-certified Taiwan Coral King coral
farm (Kaohsiung, Taiwan) is at wavelengths of 400–470 nm. Moreover, to conserve energy,
daily light exposure can be reduced to 6 h. Under these conditions, the annual output of
G. columna colonies in 150 60 30 cm glass tank can reach 3000.

Howtogrowthemcheaply

Please note of course every species is probably a little different.

The extension of coral polyps is stimulated by factors including light, water flow, and
prey [46]. Levy et al. [10] reported that tentacle expansion and contraction behavior differed
among coral types. The tentacles of Favia favus completely contracted under exposure to
light at 400–520 nm and 540–700 nm (10 mol quanta m2s1), contracted under exposure
to light at 660–700 nm (30 mol quanta m2s1) light, and extended in the absence of light.
However, Globorotalia lobata, S. pistillata, and Centruroides gracilis did not respond to light
at any of the wavelengths tested. Plerogyra sinuosa was exposed to light at 400–540 nm
(30 mol quanta m2s1). After 1–2 days, the tentacles contracted completely [10]. We
observed that G. columna achieved polyp extension rapidly under either LP or LB light at
400–470 nm (68–70 mol m2s1), with partial extension within 5 min and 100% extension
in 30 min. By contrast, the tentacles of G. columna illuminated by LG or LB (note: typo? LY?LR?) at 500–650 nm
(45–50 mol m2s1) only began to extend after 10 min, reaching 25% extension after
30 min. Furthermore, polyp shrinkage was observed in the LR and LG groups after the
experiment. Therefore, our study demonstrated that red light (620–650 nm) and green light
(500–540 nm) were unsuitable for G. columna cultivation. The most suitable wavelengths
for G. columna growth were determined to be LB (440–470 nm) and LP (400–430 nm).