Post About Wasteful Spectrum in LEDs

[saltyfilmfolks]

Wow. This thread blew up into a treasure trove of info. Bookmarked to read.

In the original question. Some colors are for looks. In all light imo. If it's for looks , technically for in relation to coral health, it's wasted.
But to enjoy the tank, it's not.

Thus my standard awnser when asked about setting led, make the tank look good , then set the intensity. Becuse I do know , you can grow coral with a light from Home Depot. I use it on my orchids now. Why exactly that is I'm still learning.
Great thread.

 

[oreo54]

Sounds good Dana. I'll see what's in the garage to build one.

note that in terrestrial plant studies 700nm light has a "timing" component..
Generally something on the line of 15min on right before lights off then ramp down, and 15min on right before lights on..then ramp off ..
Currently they are just throwing them in.. willy nilly..

PfrSpec™
With a peak spectrum at 730nm, PfrSpec™ is designed to exclusively target phytochrome far red photoreceptors. This spectrum is widely used to target Phytochrome Far Red (Pfr) in photomorphogenic lighting applications, and it is used to lengthen the dark period to encourage the flowering process in Short Day Plants.

Main point is to have them "the only" color for a brief period..Not sure they need to be "off" at all in small quantities.

Sorry very new area and take it as a "starting point" only..

 

[jda]

IR from the sun penetrates 3-4M in the ocean at high noon. That is not a lot, but nearly nobody has tank that deep, but lots of corals come from those areas? Any idea how much the IR from a typical MH would penetrate into the water? ...if it is just a few inches, then all of this might be just academic. If it can hit most of the corals, then those who have always supposed that IR mattered could be right...

I am going to have to change my rhetoric about IR waste. My many thanks to all of you.

 

[saltyfilmfolks]

I'm not sure warming from the top or from the heater in the sump would matter. Dunno really I guess. But I'd go with no.

 

[A. grandis]

IR from the sun penetrates 3-4M in the ocean at high noon. That is not a lot, but nearly nobody has tank that deep, but lots of corals come from those areas? Any idea how much the IR from a typical MH would penetrate into the water? ...if it is just a few inches, then all of this might be just academic. If it can hit most of the corals, then those who have always supposed that IR mattered could be right...

I am going to have to change my rhetoric about IR waste. My many thanks to all of you.

One of the things that makes metal halides unique IMO is the IR/UV. It could be one of the most important things the corals can "read" and to associate with coral health/ natural light. We just don't know too much about it. If some people know a bit, or think deeply about it, they won't put their words out because IR directly associated with heat and forgotten as waste. There are possibilities of combination associated with IR / spectrum/ shimmer/ UV. The projection of light in shallow water where natural shimmers are seen have so much to it! The water surface act as lenses and projects those rays. In the aquarium MHs do the same and the IR/UV is there. Differences between 250W and 400W aren't only brightness, as we know.
This is a great thread!
Grandis.

 

[Dana Riddle]

Looking for the "pressure relief" (not done looking) I found http://www.advancedaquarist.com/blog/2014/5/aafeature where you tested reds, but only 631nm and 657nm.....have you looked at 680nm and 700nm before?

I have not tested 680 and 700nm -sounds like a new experiment. The 'pressure relief valve' is the preferential excitation of Photosystem I by Far Red light (the Emerson Effect.) Walz uses a 730nm LED to induce this effect. I'm not sure off the top of my head how far into the Far Red spectrum can be used by PS I.

 

[mcarroll]

I have not tested 680 and 700nm -sounds like a new experiment. The 'pressure relief valve' is the preferential excitation of Photosystem I by Far Red light (the Emerson Effect.) Walz uses a 730nm LED to induce this effect. I'm not sure off the top of my head how far into the Far Red spectrum can be used by PS I.

Very interesting. In that case, perhaps it's simply 700nm+ that is effective for PSI, but 680nm and below is effective for PSII?

 

[Dana Riddle]

There are two maxima - P680 for PSII and P700 for PSI. In *some* cases, if there is insufficient energy for PSI, 'spill over' (state transition) of energy from PSII to PSI can happen. If PSII is the donor, and PSI is the acceptor, obviously there must be a balance between the two. If there is not enough 'stimulation' of PSI, a 'traffic jam' of energy backs up in PSII and can be damaging or destructive. So, to recap, a balance between photosystems can occur if sufficient light energy is available to the two, or if PSI is starved for energy, PSII can *in some cases* transfer energy to it (spillover.) Walz uses a 730nm LED to help drain energy from PSII.

 

[mcarroll]

Lighting is so complicated and yet so simple all at the same time. Amazing.

@Dana Riddle Thanks for that explanation!!!

 

[Dana Riddle]

Just to make sure we're on the same page - Far Red and Infra-Red are two different things.

 

[Dana Riddle]

I'll have to review the data, but spillover has been observed in some zooxanthellae. It might not be possible in all. To further complicate things, the acquisition of inorganic carbon (bicarbonate) might be limited in some due to the location (internal or external) enzymes. This could account for low compensation points, slow coral growth, etc. But then this thread is about spectrum - there I go again.

 

[mcarroll]

Just to make sure we're on the same page - Far Red and Infra-Red are two different things.

Far-red
Infrared

Their entry on far-red seems on the mark (used for fish sight, can be used for photosynthesis, etc).

But IR seems to include far-red and a whole lot more: 3.1 Commonly used sub-division scheme.

Semantics, or what definition/use case did you have in mind for IR? (Not suggesting the W is "more correct" just trying to understand.)

I know I've read (maybe even from you, not sure tho) that chlorophyl or maybe it was another pigment emit >680nm or >700nm "waste light" from the process. I think the inference was that The Deep Ocean pretty much glows far red to those that can see it or use it. Does that count as far red or IR? (Did I get that from you? )

 

[Dana Riddle]

Greater minds prevail - I agree with Wikipedia's definition of 'Far Red.' In reference to chlorophyll fluorescence, yes, fluorescence is part of energy dumping under conditions of high light - it is the basis of chlorophyll fluorometry. In this technique, the instrument can determine the rate of photosynthesis by examining chlorophyll fluorescence. In a nutshell, when fluorescence is low, the rate of photosynthesis is high and vice versa. There are three processes competing for light energy - photosynthesis, fluorescence, and heat. The PAM fluorometer can the ability to distinguish between these.

 

[mcarroll]

Greater minds prevail - I agree with Wikipedia's definition of 'Far Red.' In reference to chlorophyll fluorescence, yes, fluorescence is part of energy dumping under conditions of high light - it is the basis of chlorophyll fluorometry. In this technique, the instrument can determine the rate of photosynthesis by examining chlorophyll fluorescence. In a nutshell, when fluorescence is low, the rate of photosynthesis is high and vice versa. There are three processes competing for light energy - photosynthesis, fluorescence, and heat. The PAM fluorometer can the ability to distinguish between these.

I only loosely understood the PAM fluorometer's job before this, and not really how it worked – thanks once again!

 

[Dana Riddle]

Wow. This thread blew up into a treasure trove of info. Bookmarked to read.

In the original question. Some colors are for looks. In all light imo. If it's for looks , technically for in relation to coral health, it's wasted.
But to enjoy the tank, it's not.

Thus my standard awnser when asked about setting led, make the tank look good , then set the intensity. Becuse I do know , you can grow coral with a light from Home Depot. I use it on my orchids now. Why exactly that is I'm still learning.
Great thread.

Exactly. Over the years I've received requests from hobbyists wanting to know 'Which light is best?' After spending a ton of time formulating a reply, I would get responses such as 'My wife didn't like the look of the tank' or 'It made the carpet look purple.' So for the majority of hobbyists it is aesthetics v. function. And that's fine, it really doesn't matter to me as long as they had success with their choices. Unfortunately, none of those making these requests followed up with email responses.

 

[saltyfilmfolks]

'Which light is best?'

The one your wife likes.

I'm glad your here Dana. You'll get a lot more active responses and data points to work from.
It's really quite interesting if you're passionate about coral and light, and even more so if have a secret passion for psychology and social anthropology.

 

[mcarroll]

'Which light is best?'

+1

My auto-response for that: Define "best".

...nearly a whole other conversation from "which light".

 

[Dana Riddle]

I only loosely understood the PAM fluorometer's job before this, and not really how it worked – thanks once again!

I left out a competing process that isn't usually discussed. Besides photosynthesis, chlorophyll fluorescence, and dissipation of excess light via heat, there is coral tissue fluorescence. If we look only at Relative Electron Transport Rates between PSII and PSI (as I do), the 'pop' (I dislike that term) of coral fluorescence doesn't matter. However, if scientists are measuring the Absolute Electron Transport Rate (where absorption of light is measured), it could make a huge difference. It is generally agreed that fluorescent corals are more resistant to bleaching when exposed to high light than brown corals probably due to absorption of UV/violet/blue wavelengths which are shunted away from photosynthesis. But there is a curve ball here - Fabricius (did I spell that correctly?) reported that brown (or darker corals) tend to absorb more heat. This punches a neat hole in some theories.

 

[Dana Riddle]

The one your wife likes.

I'm glad your here Dana. You'll get a lot more active responses and data points to work from.
It's really quite interesting if you're passionate about coral and light, and even more so if have a secret passion for psychology and social anthropology.

Thank you. I was hesitant to join but am glad I did. There are some really sharp folks here, and I have learned some things here, or at least have a different perspective on some things. Acquisition of knowledge is not a destination, it is a never ending journey.

 

[Dana Riddle]

note that in terrestrial plant studies 700nm light has a "timing" component..
Generally something on the line of 15min on right before lights off then ramp down, and 15min on right before lights on..then ramp off ..
Currently they are just throwing them in.. willy nilly..


Main point is to have them "the only" color for a brief period..Not sure they need to be "off" at all in small quantities.

Sorry very new area and take it as a "starting point" only..

Requirements of terrestrial and aquatic plants are often reversed (there is a balance in nature.) Where phytochromes might play an important role on earth, in the ocean cryptochromes might be more important. There are other examples, but me, being a old fogey, am forgetful and they escape me at the moment. Thanks for your comments!