LED or T5?

[A. grandis]

I'll put the burden back on you. Show me a fluorescent lamp producing light directly absorbed by Photosystem I's P-700 (and up to 730nm or so.)
I wrote a book back in 1994 - The Captive Reef - and stated almost any light source is capable of promoting photosynthesis within zooxanthellae. Just have to understand the pros and cons of each source. I prefer LEDs, That is not to say othe rlight sources won't work. I've tried them all over the years.

I don't think many people would use such bulbs for reef tanks, but this is a great example of a bulb that would make a difference in a combo, IF ~730nm would be desirable. Also, this bulb has an uniform spectrum and higher UV (that no LED could offer) to try follow what nature is about. Not a lack of availability, but a matter of choice. "Full spectrum bulbs" are welcome in a T5 combo over a reef for many reasons, including faster growth and some of the pigments' development in some cases, as we know.

Please note the narrow bandwidth of those UV LEDs in comparison:

"UV Led 365, 385, 395, 405nm spectrums, compared with spectrum of UV Mercury traditional lamp"
FROM:

UV LED lamps emission spectrum: what's the difference with traditional UV

LED UV lamps emit a different spectrum than traditional mercury UV lamps. Discover the differences between these two technologies

www.photoelcuring.com

Also this T5 fixture:

T5 HO 2.0 4FT 4 Lamp LED Grow Light (216W Eqv.) – Sun White Spectrum

Our high efficacy T5 grow lights guarantee tighter internodal spacing & fuller, heartier plants. Innovative polycarbonate design is thin, lightweight and easy to clean. Ballast-free design means no buzzing, flickering or replacement costs.

activegrowled.com

The bulbs in the T5 fixture above show also some of the characteristics of some LEDs... again... a matter of choice, not a lack of availability.
Spectrum set to a safe uniform patter and distribution for the application it was made for (terrestrial plants).

 

[Dana Riddle]

I don't think many people would use such bulbs for reef tanks, but this is a great example of a bulb that would make a difference in a combo, IF ~730nm would be desirable. Also, this bulb has an uniform spectrum and higher UV (that no LED could offer) to try follow what nature is about. Not a lack of availability, but a matter of choice. "Full spectrum bulbs" are welcome in a T5 combo over a reef for many reasons, including faster growth and some of the pigments' development in some cases, as we know.

Please note the narrow bandwidth of those UV LEDs in comparison:

"UV Led 365, 385, 395, 405nm spectrums, compared with spectrum of UV Mercury traditional lamp"
FROM:

UV LED lamps emission spectrum: what's the difference with traditional UV

LED UV lamps emit a different spectrum than traditional mercury UV lamps. Discover the differences between these two technologies

www.photoelcuring.com

Also this T5 fixture:

T5 HO 2.0 4FT 4 Lamp LED Grow Light (216W Eqv.) – Sun White Spectrum

Our high efficacy T5 grow lights guarantee tighter internodal spacing & fuller, heartier plants. Innovative polycarbonate design is thin, lightweight and easy to clean. Ballast-free design means no buzzing, flickering or replacement costs.

activegrowled.com

The bulbs in the T5 fixture above show also some of the characteristics of some LEDs... again... a matter of choice, not a lack of availability.
Spectrum set to a safe uniform patter and distribution for the application it was made for (terrestrial plants).

Excellent, and thank you! I'm not familiar with lamps designed to grow terrestrial plants. The Power Veg lamp produces a lot of UV and in my opinion should be shielded. The other produces too much red. I would prefer narrow bandwidth LEDs in a luminaire that offers spectral tuning. But that's just me.

 

[Bpb]

I’ve always been curious. But a diode can be labeled as a specific nanometer center point. Is it really a sharp spike at that nanometer give or take 5 nm or so? Or is it really a wide smooth bell curve that many manufacturers provide? Are they smoothed our for visual cleanliness of the graphs? Or is it really accurate and does a 450nm diode really offer all manner of wavelengths down from 410 or so up to 500nm or so like a typical graph would indicate?

 

[Bpb]

Also, the OP I imagine would be grateful to receive such a degree of insight and information available now in his/her own thread

 

[this is me]

2-4 48” T5 is plenty. Fixture and retrofit is much cheaper than LEDs. Nothing lasts forever.

 

[Dana Riddle]

I’ve always been curious. But a diode can be labeled as a specific nanometer center point. Is it really a sharp spike at that nanometer give or take 5 nm or so? Or is it really a wide smooth bell curve that many manufacturers provide? Are they smoothed our for visual cleanliness of the graphs? Or is it really accurate and does a 450nm diode really offer all manner of wavelengths down from 410 or so up to 500nm or so like a typical graph would indicate?

Yes, you are correct. The peak intensity determines how the LED is labeled and their output is something like a bell curve. But the width of the bell varies and is described by its Full Width Half Maximum (FWHM.) The attached image is that of a red LED, and its FWHM is about 35 nm (eyeballing it.)

 

[Bpb]

Yes, you are correct. The peak intensity determines how the LED is labeled and their output is something like a bell curve. But the width of the bell varies and is described by its Full Width Half Maximum (FWHM.) The attached image is that of a red LED, and its FWHM is about 35 nm (eyeballing it.)

That information changes my view of leds. Thank you sir.

 

[oreo54]

I find it humorous when people talk of the "narrow" bandwidths of LED.

Generally anything past about 320-ish nm in the UV range is overall detrimental to living things.
What they do to combat that and its effects on characteristics is.. err.. arguable to say the least..and
little understood.

Error - Cookies Turned Off

onlinelibrary.wiley.com

https://www.agriculturejournals.cz/publicFiles/52840.pdf

Generally the subsequent levels of increased UV-B radiation delayed plant growth, at the same time in experiment I the differences in mean plant height at the 0, 4, 8 kJ/m2/d UV-B radiation were non-significant (ns) and only for 12 kJ/m2/d significant plant height reduction was noted. In the second experiment, harmful impact of UV-B radiation started at the low-er level of UV-B radiation at 8 kJ/m2/d.

AIl types of UV radiation are known to damage various plant processes. Such damage can be classified into two categories: damage to DNA (which can cause heritable mutations) and damage to physiological processes. There has been much speculation about how increased UV radiation exposure will affect plants, but as yet, there are no definitive answers.

http://www.plantcell.org/content/plantcell/4/11/1353.full.pdf

If you want a "positive" effect..

Indeed, pathogen resistance can be enhanced by UV treatment, and recent experiments suggest DNA damage and its processing may have a role.

Plant responses to UV radiation and links to pathogen resistance - PubMed

Increased incident ultraviolet (UV) radiation due to ozone depletion has heightened interest in plant responses to UV because solar UV wavelengths can reduce plant genome stability, growth, and productivity. These detrimental effects result from damage to cell components including nucleic acids...

www.ncbi.nlm.nih.gov

 

[A. grandis]

Yes, you are correct. The peak intensity determines how the LED is labeled and their output is something like a bell curve. But the width of the bell varies and is described by its Full Width Half Maximum (FWHM.) The attached image is that of a red LED, and its FWHM is about 35 nm (eyeballing it.)

Is that also true for T5s and metal halides?

 

[A. grandis]

I find it humorous when people talk of the "narrow" bandwidths of LED.

Generally anything past about 320-ish nm in the UV range is overall detrimental to living things.
What they do to combat that and its effects on characteristics is.. err.. arguable to say the least..and
little understood.

Error - Cookies Turned Off

onlinelibrary.wiley.com

https://www.agriculturejournals.cz/publicFiles/52840.pdf

http://www.plantcell.org/content/plantcell/4/11/1353.full.pdf

If you want a "positive" effect..

Plant responses to UV radiation and links to pathogen resistance - PubMed

Increased incident ultraviolet (UV) radiation due to ozone depletion has heightened interest in plant responses to UV because solar UV wavelengths can reduce plant genome stability, growth, and productivity. These detrimental effects result from damage to cell components including nucleic acids...

www.ncbi.nlm.nih.gov

Why would they actually produce a bulb with so much UV for terrestrial plants then? They produce a lot of bulbs with a high UV emission for terrestrial plants. I would think they know what they are doing.
Also, we have metal halides for reefs for a long long time with UV emission and they work like no other artificial light source in the market. I believe they know what they're doing as well.
Edit: What about the shallow water corals in the ocean? Tide pools? There are beautiful healthy colorful corals there!! Huge amounts of UV!

 

[Dana Riddle]

I find it humorous when people talk of the "narrow" bandwidths of LED.

Generally anything past about 320-ish nm in the UV range is overall detrimental to living things.
What they do to combat that and its effects on characteristics is.. err.. arguable to say the least..and
little understood.

Error - Cookies Turned Off

onlinelibrary.wiley.com

https://www.agriculturejournals.cz/publicFiles/52840.pdf

http://www.plantcell.org/content/plantcell/4/11/1353.full.pdf

Narrow bandwidth LED as opposed to full spectrum LED. A matter of perspective.

If you want a "positive" effect..

Plant responses to UV radiation and links to pathogen resistance - PubMed

Increased incident ultraviolet (UV) radiation due to ozone depletion has heightened interest in plant responses to UV because solar UV wavelengths can reduce plant genome stability, growth, and productivity. These detrimental effects result from damage to cell components including nucleic acids...

www.ncbi.nlm.nih.gov

 

[Dana Riddle]

If I were to build an LED light, I'd use these LEDs. I'm discussing spectral quality, not intensity:
365nm - The same output, more or less, of the mercurt spike seen in lamps containing mercury. I have some evidence that this can slightly increase coloration in some corals.
400nm - Has some UV-A as well. Useful in photosynthesis and color generation.
420nm - Same as 400nm, without the UV.
470nm - The universal light for showcasing coral fluorescence.
510nm - Absorbed by the accessory pigment peridinin and transferred to special chlorphylls in reaction centers.
587nm - There is some evidence that yellow light can generate red chromoproteins in corals.
Cool/Warm White LEDs - Provides blue and red light, along with some green. Useful in photosynthesis and is reflected by fishes, making them appear 'natural.'
730-740nm - Selectively absorbed by Pigment 700 found in Photosystem I. Possibly helps in reducing light-induced stresses in high light situations.

 

[oreo54]

If I were to build an LED light, I'd use these LEDs. I'm discussing spectral quality, not intensity:
365nm - The same output, more or less, of the mercurt spike seen in lamps containing mercury. I have some evidence that this can slightly increase coloration in some corals.
400nm - Has some UV-A as well. Useful in photosynthesis and color generation.
420nm - Same as 400nm, without the UV.
470nm - The universal light for showcasing coral fluorescence.
510nm - Absorbed by the accessory pigment peridinin and transferred to special chlorphylls in reaction centers.
587nm - There is some evidence that yellow light can generate red chromoproteins in corals.
Cool/Warm White LEDs - Provides blue and red light, along with some green. Useful in photosynthesis and is reflected by fishes, making them appear 'natural.'
730-740nm - Selectively absorbed by Pigment 700 found in Photosystem I. Possibly helps in reducing light-induced stresses in high light situations.

Here you go.. Need to add the UV/IR

* MIXING LIST
----------------------------------------
myData pcAMBER.txt [120°] x3
LED UV (400nm) [120°] x1
LED Violet (420nm) [120°] x1
LED Blue (470nm) [120°] x6
LED Cyan (510nm) [120°] x4
LED NeutralWhite (4000K) [120°] x2
----------------------------------------

* SIMULATION DATA
----------------------------------------
Luminous flux : 1,061 lm
Radiant flux : 5,289 mW
PPF : 21.7 umol/s
TCP : 28570 K
CRI : 50
λp : 468 nm
Color : #7D9AFF
----------------------------------------

* PERFORMANCE @ 30cm
----------------------------------------
Irradiance : 6.2 W/m²/s
Illuminance : 1,252 lx
PPFD : 25.6 umol/m²/s
----------------------------------------

Opps CRI is based on cool whites not neutral but it only changes by a point or 3..
The more neutral white the higher the CRI and lower the K..
6 neutral whites gives 100 "score" (I don't exactly go by that for anything esp w/ relative scales) w/ A K of 11240 and a CRI of 72.. 79 on saturated red..

you trend into the purple zone over blue though..

Oh, did use the oddball PC Amber just to get a better spread over that range..

 

[A. grandis]

If I were to build an LED light, I'd use these LEDs. I'm discussing spectral quality, not intensity:
365nm - The same output, more or less, of the mercurt spike seen in lamps containing mercury. I have some evidence that this can slightly increase coloration in some corals.
400nm - Has some UV-A as well. Useful in photosynthesis and color generation.
420nm - Same as 400nm, without the UV.
470nm - The universal light for showcasing coral fluorescence.
510nm - Absorbed by the accessory pigment peridinin and transferred to special chlorphylls in reaction centers.
587nm - There is some evidence that yellow light can generate red chromoproteins in corals.
Cool/Warm White LEDs - Provides blue and red light, along with some green. Useful in photosynthesis and is reflected by fishes, making them appear 'natural.'
730-740nm - Selectively absorbed by Pigment 700 found in Photosystem I. Possibly helps in reducing light-induced stresses in high light situations.

Great post. That is exactly what I was waiting for. I appreciate this very much in many ways! It is what is the most important to start the understanding of what we know today about the optimal utilization by zooxanthellae.
What would be the percentage of each diode for a perfect (or near perfect in your opinion) spectrum efficiency in your opinion?
Thanks!

 

[Dana Riddle]

Great post. That is exactly what I was waiting for. I appreciate this very much in many ways! It is what is the most important to start the understanding of what we know today about the optimal utilization by zooxanthellae.
What would be the percentage of each diode for a perfect (or near perfect in your opinion) spectrum efficiency in your opinion?
Thanks!

That would require a good deal of research. I'd have to determine the intensity generated by each diode and examine PUR of each. What many consider the gospel nowadays took a lot of research back in the 90's.

 

[A. grandis]

That would require a good deal of research. I'd have to determine the intensity generated by each diode and examine PUR of each. What many consider the gospel nowadays took a lot of research back in the 90's.

Thanks very much, Dana. Let's wait then.

 

[TerraFerma]

Excellent, and thank you! I'm not familiar with lamps designed to grow terrestrial plants. The Power Veg lamp produces a lot of UV and in my opinion should be shielded. The other produces too much red. I would prefer narrow bandwidth LEDs in a luminaire that offers spectral tuning. But that's just me.

For what it's worth - most of the indoor farmers out here still use MH for most of the plant's life cycle. And for seedlings/clones...they use...T5. So they aren't quite sold on LED's yet.
I have buddies that have done it with LED's (high end fixtures) on a small scale. The results seem fine to me. Big power bill savings and they are able to grow in places where the heat from MH would have been a total non starter. A lot of the high end LED grow fixtures go out of their way to up UVA (it's important in the later part of the plants life cycle, and they mostly do this by adding normal T8 UVA bulbs, although a few manufacturers claim to do UVA with LED's ). As of yet no suitable LED has been found to produce meaningful amounts of UVB (along the lines of a MH), which also has beneficial effects later in the plant's life cycle (at least as far as the end product is concerned).

Back to coral: I've always had better growth and color with T5's than LED's. And specifically - under a whiter bulb combo that lets me actually see the corals and the whole tank in full light that my eye can take in. The corals just seem happier and healthier and easier to take care of. Turning up the whites on an LED fixture has never produced a color temp that is pleasing to my eye and renders good colors in coral. Which is why I assume everyone with an LED fixture is obsessed with just running blues. Radion just came out with a "blue" fixture...

Replacing T5 bulbs is never fun. But I didn't get into this hobby to save money.

 

[oreo54]

As of yet no suitable LED has been found to produce meaningful amounts of UVB (along the lines of a MH), which also has beneficial effects later in the plant's life cycle (at least as far as the end product is concerned).

UVB Light And Boosting THC Potency - California LightWorks

UVB light can help boost the potency of cannabis but over-use can damage your yield. Learn how UVB works and best practices here.

news.californialightworks.com

One of these changes caused by this reaction is very important in your cannabis garden. UV stress stimulates cannabis’ production of chemicals via the phenylpropanoid pathway, specifically malonyl-CoA and phenylalanine. Why is this important? Because cannabis uses malonyl-CoA to make Olivtol, which it in turn uses to make THC. So finally the specific pathway which increases Cannabis potency when exposed to UV light is understood, and we can use this information to our advantage... Many growers have been aware of the benefits of UVB and have used supplemental lighting to boost potency. However, be aware, there is a threshold where the damage to yield caused by high level UVB will exceed any benefits in potency, so caution and careful design protocols MUST be used when attempting to supplement UVB. It is also VERY important to be EXTREMELY careful using off-the-shelf UVB sources like lizard lights that are not specifically designed for human exposure, because while sunlight has quite high levels of UVB, the intensity of the sun prevents people from staring straight at it. UVB is invisible, so your eyes can’t tell you if they are getting too much UVB from a UVB light source in your grow room, and your eyes and skin can be damaged if the levels are too high. So it’s worth repeating: Extreme caution must be observed when using secondary UVB supplementation.

Not sure how that impacts corals..

Explaining UV and Cannabis

www.solacure.com

Super B - High UVB T8 Bulb

www.solacure.com

 

[TerraFerma]

UVB Light And Boosting THC Potency - California LightWorks

UVB light can help boost the potency of cannabis but over-use can damage your yield. Learn how UVB works and best practices here.

news.californialightworks.com

Not sure how that impacts corals..

Explaining UV and Cannabis

www.solacure.com

People with MH/T5 seem to have better results/experiences with coral, hence the masses switching back from LED. Ditto with the cousin. The sun grows both plants and corals.

 

[oreo54]

hence the masses switching back from LED

Like to see that quantified or it's just propaganda..

supplementing MH OR LED w/ t5's maybe..