6500k T5 Bulbs - Important Spectrums Missing in LEDs?

[oreo54]

Here we venture into unknown territory (at least it is not known by myself.) Until detailed laboratory experiments are conducted with the several hundred types of zooxanthellae and we understand how common - or not - Spillover is, it is likely that exposure to radiation at 730nm will do no harm and quite possibly beneficial.

More interested in the converse.. Is the lack of 730nm or low levels an err "issue"?..
Doesn't take too long in nature to have IR in short supply..

 

[Reefahholic]

Got my Saturday chores done - maybe cutting grass for the last time until Spring! Yay!
Here's the scoop on LEDs generating radiation peaking at 730nm. But first, some background.
In a quirk of nomenclature, Photosystem II transfers collected photons (now in the form of electrons) to Photosystem I (so named because it was discovered first.) Chlorophylls and Accessory (or Antennae) Pigments collect light and channel it to Reactions Centers. The Reaction Centers in Photosystem II absorb light at 680nm (hence these are called Pigment 680 or P-680.) The Reaction Centers in Photosystem I absorb light at 700nm (Pigment 700, or P-700.) There must be a balance of electron flow between Photosystem II and Photosystem I or damage can occur (Photosystem II acts as the electron donor, and Photosystem I the acceptor. If Photosystem I cannot accept electrons from Photosystem II, a 'traffic jam of electrons occurs.) Photosystem I can absorb light at 730nm and this helps in preventing the 'traffic jam.' Now, what happens when no far red light is available (such as we would see at depth?) In these cases, something called a 'State Transition' or 'Spill Over' of energy from PSII to PSI possibly occurs, thus stimulating PSI and allowing it to accept the electrons from PSII. Is this possible in all zooxanthellae species/clades/types? Here we venture into unknown territory (at least it is not known by myself.) Until detailed laboratory experiments are conducted with the several hundred types of zooxanthellae and we understand how common - or not - Spillover is, it is likely that exposure to radiation at 730nm will do no harm and quite possibly beneficial.

Got my Saturday chores done - maybe cutting grass for the last time until Spring! Yay!
Here's the scoop on LEDs generating radiation peaking at 730nm. But first, some background.
In a quirk of nomenclature, Photosystem II transfers collected photons (now in the form of electrons) to Photosystem I (so named because it was discovered first.) Chlorophylls and Accessory (or Antennae) Pigments collect light and channel it to Reactions Centers. The Reaction Centers in Photosystem II absorb light at 680nm (hence these are called Pigment 680 or P-680.) The Reaction Centers in Photosystem I absorb light at 700nm (Pigment 700, or P-700.) There must be a balance of electron flow between Photosystem II and Photosystem I or damage can occur (Photosystem II acts as the electron donor, and Photosystem I the acceptor. If Photosystem I cannot accept electrons from Photosystem II, a 'traffic jam of electrons occurs.) Photosystem I can absorb light at 730nm and this helps in preventing the 'traffic jam.' Now, what happens when no far red light is available (such as we would see at depth?) In these cases, something called a 'State Transition' or 'Spill Over' of energy from PSII to PSI possibly occurs, thus stimulating PSI and allowing it to accept the electrons from PSII. Is this possible in all zooxanthellae species/clades/types? Here we venture into unknown territory (at least it is not known by myself.) Until detailed laboratory experiments are conducted with the several hundred types of zooxanthellae and we understand how common - or not - Spillover is, it is likely that exposure to radiation at 730nm will do no harm and quite possibly beneficial.

Dana, I really appreciate your work and have watched your lighting presentations more than you'll ever know. That said...I'll never be as knowledgeable as you when it comes to lighting. I've also seen other studies that agree with your evidence. One thing that keeps me up at night is the data you collected in Hawaii with the Proites coral. You clearly see that it didn't like the intense light and actually declines or stops photosynthesis. The you showed the deeper Proites which is impressive and had to be growing for 100 years or longer. Point being it was in less light. Point well taken. Yet...it definitely appears that cooking these corals in intense light is yielding better results. Why do you suspect this is? Does a coral have to show photosynthesis on a meter in order to grow? I'd think so, but if you measured 400 PAR on an acropora dominated reef and 120 PAR on another...I'd be willing to bet that the tank receiving the higher PAR would grow faster despite the meter readings?

It just really doesn't make sense, but I've experience it with my own reef and have turned it down a few times only to find my Alkalinity demand dropping. I would love to hear an explanation as to why the studies are showing one thing, but appear to be contradicting what I'm seeing and observing myself.

 

[Reefahholic]

I fully intend on attempting a comparison of 10k mh in a quality reflector against a quality led fixture in the next year in an adequately large and controlled system with regards to acropora. I will not for one minute consider myself an authority or a final say, just hope to add anecdotal data to the pool. This will be a long running “experiment” similar to how Adam at BC does it. With identical samples of pieces in a closed system over a long time period.

That sir has me very interested. Please PM when this begins!

 

[Lasse]

I often do a "thinking hard disk error" when I look at a curve of absorption rate. I do not take with the intensity of the light (wavelength) in the equation and say that this is not good. I have to think of light as photons in order to understand the real meaning of percent penetration. Let us say that if you start with 1000 photons and there is a loss of 80% at 5 m. It means that there will still be 200 photons at 5 m. Now you add a similar light source very tight to the other - both together will produce 2000 photons - and there will be 400 at the depth of 5 m - and so on.

I really doesn't make sense, but I've experience it with my own reef and have turned it down a few times only to find my Alkalinity demand dropping. I would love to hear an explanation as to why the studies are showing one thing, but appear to be contradicting what I'm seeing and observing myself.

Probably was not your light intensity close to the saturation level IMO

Sincerely Lasse

 

[Dana Riddle]

Thank´s for the clarifying

Sincerely Lasse

You betcha Lasse.

 

[Dana Riddle]

More interested in the converse.. Is the lack of 730nm or low levels an err "issue"?..
Doesn't take too long in nature to have IR in short supply..

At least two possibilities here. 'Spill over' (State Transition) or Chromatic Adaptation by photopigments to balance electron flow.

 

[Dana Riddle]

Dana, I really appreciate your work and have watched your lighting presentations more than you'll ever know. That said...I'll never be as knowledgeable as you when it comes to lighting. I've also seen other studies that agree with your evidence. One thing that keeps me up at night is the data you collected in Hawaii with the Proites coral. You clearly see that it didn't like the intense light and actually declines or stops photosynthesis. The you showed the deeper Proites which is impressive and had to be growing for 100 years or longer. Point being it was in less light. Point well taken. Yet...it definitely appears that cooking these corals in intense light is yielding better results. Why do you suspect this is? Does a coral have to show photosynthesis on a meter in order to grow? I'd think so, but if you measured 400 PAR on an acropora dominated reef and 120 PAR on another...I'd be willing to bet that the tank receiving the higher PAR would grow faster despite the meter readings?

It just really doesn't make sense, but I've experience it with my own reef and have turned it down a few times only to find my Alkalinity demand dropping. I would love to hear an explanation as to why the studies are showing one thing, but appear to be contradicting what I'm seeing and observing myself.

Many questions. Few answers. But I can speculate. There are at least several hundred types (species, clades.) Some clades are highly adaptable to high/low light fields. Others do poorly in high light. Some do poorly in low light.
Large branching coral corals can self-shade and have high zoox concentrations in the shaded portions and low concentrations in illuminated sections.
I recently measured chlorophyll content in an aquarium Acropora and found the illuminated section to contain 800 milligrams per square meter. How? Why? Higher nutrient loading? High alkalinity?
As for higher photosynthesis and higher coral growth. It is known that photosynthesis/high zoox concentrations would have a higher nutrient demand, including phosphorus. Phosphorus is a known enemy of calcification, so would high zoox demand for phosphorus be enough to encourage calcification?
I wish I had a definitive answer. But I know what I don't know.

 

[Mortie31]

I fully intend on attempting a comparison of 10k mh in a quality reflector against a quality led fixture in the next year in an adequately large and controlled system with regards to acropora. I will not for one minute consider myself an authority or a final say, just hope to add anecdotal data to the pool. This will be a long running “experiment” similar to how Adam at BC does it. With identical samples of pieces in a closed system over a long time period.

Not being rude, but why?? Metal halides are the past, whilst I fully accept that LEDs are not perfect yet, surely we need to be challenging the LED manufacturers to improve their products in terms of spectrum and coverage, rather than dreaming of yesterday’s technology, I’m sure MH’s will cling on for several more years with some members, but they certainly aren’t the future. If there are spectrum gaps in certain LEDS then comparisons between manufacturers and models would surely be of more value, as highlighting competitor advantages/ weaknesses will help drive the technology further faster, or are T5/LED hybrids the real future??

 

[Bpb]

Not being rude, but why?? Metal halides are the past, whilst I fully accept that LEDs are not perfect yet, surely we need to be challenging the LED manufacturers to improve their products in terms of spectrum and coverage, rather than dreaming of yesterday’s technology, I’m sure MH’s will cling on for several more years with some members, but they certainly aren’t the future. If there are spectrum gaps in certain LEDS then comparisons between manufacturers and models would surely be of more value, as highlighting competitor advantages/ weaknesses will help drive the technology further faster, or are T5/LED hybrids the real future??

No rudeness taken. And I truly mean the same back to you, no rudeness intended here, but I’m not real concerned with terms like “the past” and “the future”. I currently am a metal halide user. I’ve made the lighting rounds before and tried out many options over the years. They all have their merits. But metal halides are still available, and will continue to be available until they aren’t. I have no interest in trying to speed up the inevitable. There’s nothing in that for me. I like using metal halides because of their ease of installation and operation. On a small to medium scale, I have not found the energy use, temperature, or bulb schedule to be in any way deterring.

 

[Mortie31]

No rudeness taken. And I truly mean the same back to you, no rudeness intended here, but I’m not real concerned with terms like “the past” and “the future”. I currently am a metal halide user. I’ve made the lighting rounds before and tried out many options over the years. They all have their merits. But metal halides are still available, and will continue to be available until they aren’t. I have no interest in trying to speed up the inevitable. There’s nothing in that for me. I like using metal halides because of their ease of installation and operation. On a small to medium scale, I have not found the energy use, temperature, or bulb schedule to be in any way deterring.

I fully understand why you like MH and if all things were equal I doubt anyone who keeps SPS would use anything other than them, everyone knows there better than the LEDs we currently have, so why do your experiment? The trouble is things arent equal, and alternative ways of doing things need to be driven...but that’s a very philosophical and controversial discussion probably best not ventured into on our forum..

 

[Bpb]

I fully understand why you like MH and if all things were equal I doubt anyone who keeps SPS would use anything other than them, everyone knows there better than the LEDs we currently have, so why do your experiment? The trouble is things arent equal, and alternative ways of doing things need to be driven...but that’s a very philosophical and controversial discussion probably best not ventured into on our forum..

You’re right to ask that question , and there are a couple reasons for it. I’ll detail them in the build thread when the time comes.

 

[Reefahholic]

Many questions. Few answers. But I can speculate. There are at least several hundred types (species, clades.) Some clades are highly adaptable to high/low light fields. Others do poorly in high light. Some do poorly in low light.
Large branching coral corals can self-shade and have high zoox concentrations in the shaded portions and low concentrations in illuminated sections.
I recently measured chlorophyll content in an aquarium Acropora and found the illuminated section to contain 800 milligrams per square meter. How? Why? Higher nutrient loading? High alkalinity?
As for higher photosynthesis and higher coral growth. It is known that photosynthesis/high zoox concentrations would have a higher nutrient demand, including phosphorus. Phosphorus is a known enemy of calcification, so would high zoox demand for phosphorus be enough to encourage calcification?
I wish I had a definitive answer. But I know what I don't know.

Agreed, so many questions and so few answers. I’ve noticed my black Mangrove will tilt its leaves when it’s receiving too much light. Self-Shading is very interesting topic. Every year we learn more and more. So interesting to follow your studies as well as others.

 

[Reefahholic]

Not being rude, but why?? Metal halides are the past, whilst I fully accept that LEDs are not perfect yet, surely we need to be challenging the LED manufacturers to improve their products in terms of spectrum and coverage, rather than dreaming of yesterday’s technology, I’m sure MH’s will cling on for several more years with some members, but they certainly aren’t the future. If there are spectrum gaps in certain LEDS then comparisons between manufacturers and models would surely be of more value, as highlighting competitor advantages/ weaknesses will help drive the technology further faster, or are T5/LED hybrids the real future??

I wouldn’t say metal halides are the past. Still plenty people running them and from what I’ve observed over the last 15 years is they are growing coral far better than most options out there.

 

[Reefahholic]

No rudeness taken. And I truly mean the same back to you, no rudeness intended here, but I’m not real concerned with terms like “the past” and “the future”. I currently am a metal halide user. I’ve made the lighting rounds before and tried out many options over the years. They all have their merits. But metal halides are still available, and will continue to be available until they aren’t. I have no interest in trying to speed up the inevitable. There’s nothing in that for me. I like using metal halides because of their ease of installation and operation. On a small to medium scale, I have not found the energy use, temperature, or bulb schedule to be in any way deterring.

Bpd, I’d like to try MH’s but always worry about my electric bill and heat. Looking at the last statement of your reply here makes me feel better. How much increase would I be seeing on my electric bill? Can you get away with fans running MH’s are is a chiller a must.? Thx!

 

[CO2doser]

I suggest to do a comparison that T5, MH, and LED all set at 6500k at high par like 500par. Since the weakness of LED is burnt coral at more white like and very intensive light while MH had demonstrated good growth without burnt.

If comparison is under blue light more setting, I do not think will get meaningful result.

The purpose of comparison is to find what missing in LED to improve the technology.

 

[GlassMunky]

Not being rude, but why?? Metal halides are the past, whilst I fully accept that LEDs are not perfect yet, surely we need to be challenging the LED manufacturers to improve their products in terms of spectrum and coverage, rather than dreaming of yesterday’s technology, I’m sure MH’s will cling on for several more years with some members, but they certainly aren’t the future. If there are spectrum gaps in certain LEDS then comparisons between manufacturers and models would surely be of more value, as highlighting competitor advantages/ weaknesses will help drive the technology further faster, or are T5/LED hybrids the real future??

So somewhat analogous in my mind here is all the legal states and Canada now having access to legal cannabis, ALOT of grow shops and users are still sticking with CMH lamps over LED due to a better spectrum giving better yields and results even with the power/heat savings of LED.
I’m wondering if it has to do with the CRI of these new Phillips AGRO elite bulbs which have a CRI of about 92.
CRI describes how the color of a light source changes how an object appears to the human eyes and how well subtle variations in color shades are revealed. The higher the CRI, the more realistic things look. CMH grow lights are generally rated between 80 to 96 CRI, by comparison, the sun is rated at 100 CRI.
Has anyone thought or tried using these almost sun-like bulbs compared to traditional 6500-20k MH bulbs we use in reef keeping?
I’d be interested to see how quickly those grow acros

 

[Bpb]

Bpd, I’d like to try MH’s but always worry about my electric bill and heat. Looking at the last statement of your reply here makes me feel better. How much increase would I be seeing on my electric bill? Can you get away with fans running MH’s are is a chiller a must.? Thx!

Man, I know people here in Texas that use a chiller and are on all leds. So it’s hard to say. I can only give my experience. I’m in central Texas. I have 2x250 watt halides in a canopy. No chiller. I just use 2 clip on desk fans pointed at the water and my temps stay between 78-79. I Evap about a gallon a day from 87 net gallons of water, and the ac is set to 74.

 

[Bpb]

So somewhat analogous in my mind here is all the legal states and Canada now having access to legal cannabis, ALOT of grow shops and users are still sticking with CMH lamps over LED due to a better spectrum giving better yields and results even with the power/heat savings of LED.
I’m wondering if it has to do with the CRI of these new Phillips AGRO elite bulbs which have a CRI of about 92.
CRI describes how the color of a light source changes how an object appears to the human eyes and how well subtle variations in color shades are revealed. The higher the CRI, the more realistic things look. CMH grow lights are generally rated between 80 to 96 CRI, by comparison, the sun is rated at 100 CRI.
Has anyone thought or tried using these almost sun-like bulbs compared to traditional 6500-20k MH bulbs we use in reef keeping?
I’d be interested to see how quickly those grow acros

I may have to give one of those a try. Note what appears to be a discrete bump at 730. Nice

 

[Mortie31]

I wouldn’t say metal halides are the past. Still plenty people running them and from what I’ve observed over the last 15 years is they are growing coral far better than most options out there.

It’s strange but this in another area where US reefers appear to differ from the rest of the world, to see anyone with Mh in Europe/ Asia is very rare... T5 and LEDs dominate over here with T5 having a far higher amount of use than in the US. I’d be interested see what % of US reefers still use MH.

 

[ycnibrc]

Well I have play with most light on the market but at the end I always go back to halide. I bought some radion g4 pro a few months ago but the blue color is a little over saturated. So I sold it n get the orphek atlantik v4 g2. The color is much more natural and they have yellow n Amber led in their light panel. Only a couple months but I love the mix of orphek n 20k halide. It's magical. The video don't show the real color of the light. It's soothing to the eye.