LED's
- Thread starter mojoreef
- Start date
Help Support Reef Aquarium & Tank Building Forum:
Krish
RF STAFF
You know I never burnt a coral putting them directly under a 250w metal halide in my 38 gal cube where some of the corals were almost extended to the water's surface so they got hit with everything my light had! I wonder if it has anything to do with my frags coming directly out of the wild in knee high water sometimes which was exposed to the sun? 
. You guys need tougher corals eace:
L.E.D's = over rated! :nono:
Metal Halides - FTW!
You guys impress me and make me change my mind.
(BTW, Good topic Mojo. Also, guys acclimate your corals. Don't mind my chit chat. There is a difference between wild caught and store bought.)
. You guys need tougher corals eace: L.E.D's = over rated! :nono:
Metal Halides - FTW!
You guys impress me and make me change my mind.
(BTW, Good topic Mojo. Also, guys acclimate your corals. Don't mind my chit chat. There is a difference between wild caught and store bought.
)
Last edited:
Katchupoy
Well-known member
Im jumping on board.... i dont know if i have something to add but i've been with 100% led since January. I want to know, if i made a mistake with the decision... or what is this PUR, PAR, LUMENS... I know what it means but I want to hear what you all of you want to share....
tat2z_21
tat2z_21
PAR-
PAR, or photosynthetically active radiation, is a measure of how much light energy is present that may be used in all known instances of photosynthesis. This is a measure of how many radiation particles hit a meter square of space in one second. PAR is the best to date way to easily measure actual usable light. The problem with PAR is that it measures light within all usable wavelengths, and most photosynthetic organisms aren’t capable of using all of these wavelengths. This means that a PAR reading may not be truly showing how much energy is being emitted that your corals or plants can use. This is where PUR comes in.
This next part is more of a theory than a science based measurement NO MATTER WHAT ANYONE TELLS YOU! PUR, or photosynthetically usable radiation, is a measure of of how much PAR is present in the wavelengths specifically useful to a designated animal or plant. As depth increases light falls off more in some wavelengths than others, so corals that live deeper are more adapt at using specific wavelengths for photosynthesis. There may be a meter capable of measuring PAR in very specific wavelengths only, but the problem with this is finding the exact wavelengths a coral uses. This is why I say that PUR is a theory not an exact science. If it were possible to find out exactly which wavelengths a coral is capable of using and measure for only those, you could calculate anexact number for PUR. Corals are also very adaptive animals and can adapt or adopt new xooanthelia that may use new wavelengths, so PUR for some corals may be exactly the same as PAR.
This is where the complicated subject of aquarium lighting often gets derailed. Some insist that PAR is useless compared to PUR, but with the adaptive ever changing nature of coral, it’s hard to pin down exactly which wavelengths to test for.
The lumen is one of the most misunderstood and most misquoted values used in describing light output. A lumen is simply a measure of total visible light energy (luminous-flux) produced by a light source, and as such, does not consider the area over which it might be spread. Said another way, it is a measurement of the energy emitted by the bulb that the eye can actually see. So, it is very similar to a watt. Like a watt, it is also independent of distance. A 100 lumen bulb is a 100 lumen bulb at ten feet or ten miles.
Hope this helps clarify things when it comes to these terms.
It is my understanding that though PUR is a valuable part of our reef system, it is also totally up to the individual coral, and the xooanthelia that is present, that decides what PUR is needed and what is not. And since each individual coral may be different it is impoosible to actually accommodate each coral. Corals thrive at different depths of the ocean. With this there is a different spectrum the deeper you go. Meaning that the PUR would be different for corals at a deeper depth.
PAR, or photosynthetically active radiation, is a measure of how much light energy is present that may be used in all known instances of photosynthesis. This is a measure of how many radiation particles hit a meter square of space in one second. PAR is the best to date way to easily measure actual usable light. The problem with PAR is that it measures light within all usable wavelengths, and most photosynthetic organisms aren’t capable of using all of these wavelengths. This means that a PAR reading may not be truly showing how much energy is being emitted that your corals or plants can use. This is where PUR comes in.
This next part is more of a theory than a science based measurement NO MATTER WHAT ANYONE TELLS YOU! PUR, or photosynthetically usable radiation, is a measure of of how much PAR is present in the wavelengths specifically useful to a designated animal or plant. As depth increases light falls off more in some wavelengths than others, so corals that live deeper are more adapt at using specific wavelengths for photosynthesis. There may be a meter capable of measuring PAR in very specific wavelengths only, but the problem with this is finding the exact wavelengths a coral uses. This is why I say that PUR is a theory not an exact science. If it were possible to find out exactly which wavelengths a coral is capable of using and measure for only those, you could calculate anexact number for PUR. Corals are also very adaptive animals and can adapt or adopt new xooanthelia that may use new wavelengths, so PUR for some corals may be exactly the same as PAR.
This is where the complicated subject of aquarium lighting often gets derailed. Some insist that PAR is useless compared to PUR, but with the adaptive ever changing nature of coral, it’s hard to pin down exactly which wavelengths to test for.
The lumen is one of the most misunderstood and most misquoted values used in describing light output. A lumen is simply a measure of total visible light energy (luminous-flux) produced by a light source, and as such, does not consider the area over which it might be spread. Said another way, it is a measurement of the energy emitted by the bulb that the eye can actually see. So, it is very similar to a watt. Like a watt, it is also independent of distance. A 100 lumen bulb is a 100 lumen bulb at ten feet or ten miles.
Hope this helps clarify things when it comes to these terms.
It is my understanding that though PUR is a valuable part of our reef system, it is also totally up to the individual coral, and the xooanthelia that is present, that decides what PUR is needed and what is not. And since each individual coral may be different it is impoosible to actually accommodate each coral. Corals thrive at different depths of the ocean. With this there is a different spectrum the deeper you go. Meaning that the PUR would be different for corals at a deeper depth.
Yeah that's what I'm saying....:closed_2:
Actually i will get back to you in a time of less drinking....like tomorrow.
What I will say though is Yes LEDS produce more and consistent PUR over a given time. This is mostly doe to the spectrum of the light I would suspect. We all know that over lighting can eventually cause Zooaxelle(sp?) bailout or bleaching whatever you want to call it. And Tat2z already explained that PUR is dependent on the individual coral/animal. So now you take a light say MH that has produced 200 par and 100 pur for the SPS at the top of your tank, but the spectrum of the LEDs because of both the spot light, individual color spectrums etc produces 200 par and 200 PUR. Then obviously you would need to reduce the LED to to match the 100 Pur and raise it slowly to acclimate.
Basically I am trying to say that is light A produces a spectrum that is 200 pur at 200 par and the other is 100 pur at 200 par then you will need to adjust either duration or intensity.
Last edited:
10gnano
Well-known member
following this one. I just ordered a ai sol blue and had concerns with high levels of PAR and PUR, on the upside this fixture is dimmable. My understanding is that the corals will adjust over a period of time to thrive in the environment that it is presented with.
Ok lets take a bit of a closer look at this then and I and I am asking because their is alot of BS out thier (as we all know in reefing) and I would like a cleaner view of things as I might dive into using them. So here we go.
Floyd, I thought I could stir you from the shadows lol.
Ok yea, the particles are called photons and those puppies are what corals use to convert light energy to a biological energy source for the corals. The range for PAR is any light wave between 400 and 700 nanometers and it is measured in the form of Einsteins ( unit µE/m[SUP]2[/SUP]/s)
Ok when you look at corals and lighting you have to look at it in two ways. The first way is the light energy (photons) that we deliver to corals for them to use and convert into biological energy. So corals use their zoox to do this, and the zoox use their pigments to accomplish is. ZOOx have 2 basic pigments, chlorophyll’s which are green and carotenoid peridinin which is yellow, but they can have these pigments in various quantities of either (based on the species of zoox). They like light waves in the violet to blue zone. So maybe this is what folks are trying to say PUR is??
Anyway the second way: Corals have a variety of pigments in their tissue that are not with in the ZOOX. They use these pigments in two ways, one is for UV protection (but most of those are transperent) and then the other is for fluorescing, which is kindo of cool. Basically this fluorescing pigment will absorb a light wave that is not usable by zoox and re-emit a usuable light wave to the zoox, this is called fluorescing. Now corals can have many of these pigments in various dencity levels and they get kind of deep on that. As in they can cross link across many pigments to finally come up with one that is usable, so one pigment take a light wave, truns it into another light wave, then that one is taken by another pigment and coverted to a usuable on, so many absorbs and fluoresces later can produce PUR?? So if you want to have a more detailed explanation go here http://www.reeffrontiers.com/forums/f69/some-light-info-ya-59098/
Ok so if we know that PUR apperently measures usable light, which is light used by zoox, which have two pigments that are yellow and green (which when mixed create brown) and the fact we know that through the use of tissue pigment a coral has the ability to convert other PAR light waves (the pretty ones) into PUR ones then then debate on PUR vs PAR is not all that important to the hobbist.
Oh on the lumins their useless to us so lets not even go their, I have muddied up this enough already, lol
:focus:
So then by saying this you are saying that LED's produce alot of violet to blue lighting, which is VERY inportant when looking at the use of these. I will do some phone calling and research on the spectrums put out by various LED's and post them up in a bit. This is something I am interested in. On the bailout/bleaching thing, I will give you a quick and dirty on it. As with any photosynthetic critter (in the case of corals the zoox) it absorbs co2 and emits oxygen. In the coral this can be a very bad thing when it is over done as it can led to the creation of a super radical oxidizer. SO kind of a ozone generator with in the coral itself, which we no will begin to oxidize the coral itself (Disintegrate). The coral has a built in reaction that releases an enzyme which makes the corals bail out its zoox, Kind of like the Enterprize ejecting the core before it melts down.
Alright then so I think the next thing to look at is some spectral charts of various LEDS to see if their is something going on their. I will dig and come back so keep the input coming.
Mojo
Over priced for sure, not sure about the over rated anymore.
Floyd, I thought I could stir you from the shadows lol.
Ok yea, the particles are called photons and those puppies are what corals use to convert light energy to a biological energy source for the corals. The range for PAR is any light wave between 400 and 700 nanometers and it is measured in the form of Einsteins ( unit µE/m[SUP]2[/SUP]/s)
Ok so PUR is saying that along that 400 to 700 nm range that only certain waves matter and others dont and that PUR is just talking about them and nothing else. Which is Kind of BS (we will talk about that in a little bit) now in order to measure PUR you would have to measure individual waves for the amount of photons they produce and then line that up with what ever type of Zoox the coral has and whatever pigment is dominate in the coral, So since we dont have that ability and that their are to many variables PUR is a nice word but really cant be used, so does it really pertain???
Actualy we can nail that puppy donw really easy, with out have to worry about debating PAR vs PUR so lets get this puppy put to bed so we can move on to the subject at hand.
Ok when you look at corals and lighting you have to look at it in two ways. The first way is the light energy (photons) that we deliver to corals for them to use and convert into biological energy. So corals use their zoox to do this, and the zoox use their pigments to accomplish is. ZOOx have 2 basic pigments, chlorophyll’s which are green and carotenoid peridinin which is yellow, but they can have these pigments in various quantities of either (based on the species of zoox). They like light waves in the violet to blue zone. So maybe this is what folks are trying to say PUR is??
Anyway the second way: Corals have a variety of pigments in their tissue that are not with in the ZOOX. They use these pigments in two ways, one is for UV protection (but most of those are transperent) and then the other is for fluorescing, which is kindo of cool. Basically this fluorescing pigment will absorb a light wave that is not usable by zoox and re-emit a usuable light wave to the zoox, this is called fluorescing. Now corals can have many of these pigments in various dencity levels and they get kind of deep on that. As in they can cross link across many pigments to finally come up with one that is usable, so one pigment take a light wave, truns it into another light wave, then that one is taken by another pigment and coverted to a usuable on, so many absorbs and fluoresces later can produce PUR?? So if you want to have a more detailed explanation go here http://www.reeffrontiers.com/forums/f69/some-light-info-ya-59098/
Ok so if we know that PUR apperently measures usable light, which is light used by zoox, which have two pigments that are yellow and green (which when mixed create brown) and the fact we know that through the use of tissue pigment a coral has the ability to convert other PAR light waves (the pretty ones) into PUR ones then then debate on PUR vs PAR is not all that important to the hobbist.
Oh on the lumins their useless to us so lets not even go their, I have muddied up this enough already, lol
:focus:
So then by saying this you are saying that LED's produce alot of violet to blue lighting, which is VERY inportant when looking at the use of these. I will do some phone calling and research on the spectrums put out by various LED's and post them up in a bit. This is something I am interested in. On the bailout/bleaching thing, I will give you a quick and dirty on it. As with any photosynthetic critter (in the case of corals the zoox) it absorbs co2 and emits oxygen. In the coral this can be a very bad thing when it is over done as it can led to the creation of a super radical oxidizer. SO kind of a ozone generator with in the coral itself, which we no will begin to oxidize the coral itself (Disintegrate). The coral has a built in reaction that releases an enzyme which makes the corals bail out its zoox, Kind of like the Enterprize ejecting the core before it melts down.
Alright then so I think the next thing to look at is some spectral charts of various LEDS to see if their is something going on their. I will dig and come back so keep the input coming.
Mojo
tat2z_21
tat2z_21
So this spectralgraph is from a regular 3w white led.
If you notice the white has a huge peak at the 450nm, then you figure that most leds have a 1 for 1 white and blue led combo. So maybe all in all we are over loading our corals with that PUR.
If you notice the white has a huge peak at the 450nm, then you figure that most leds have a 1 for 1 white and blue led combo. So maybe all in all we are over loading our corals with that PUR.
tat2z_21
tat2z_21
When producing a white LED they have to add several colored LED's into the chip in order to get the exact color rendering that they are looking for. Obviously in blues it is just blue, and yellow it is just yellow, and so on and so on. But when it comes to white light it is opposite from a regular color wheel. If you take all of the primary colors in aint and add them together you get black, but with light spectrums if you add all of the colors together it becomes white.
Yea Floyd I see the peek in the range but ALL MH's have the same kind of spike/spikes so hard to put it on that. I am not sure what 'counts" are though, do you??
If this the statement that led's have a more intence production in a particular wavelength then we need to standardize the measurements. So I am looking for a chart that deals with spectral irradiance on the side bar. Find that and we are dancing.
Mojo
If this the statement that led's have a more intence production in a particular wavelength then we need to standardize the measurements. So I am looking for a chart that deals with spectral irradiance on the side bar. Find that and we are dancing.
Mojo
tat2z_21
tat2z_21
The Mambo......
Katchupoy
Well-known member
In addition to what Akunochi was saying based on LED producing more consistent spectrum compared to MH and T5...
I believe the simple explanation to this phenomenon is because of technology... Both T5 and MH uses special gas and phosphors that degrades over time (which is also called cycling) while LED technology are based on solid state, thus no gas to degrade overtime.
I believe the simple explanation to this phenomenon is because of technology... Both T5 and MH uses special gas and phosphors that degrades over time (which is also called cycling) while LED technology are based on solid state, thus no gas to degrade overtime.
Katchupoy
Well-known member
Last edited:
tat2z_21
tat2z_21
I have found several that measure with spectral relative light intensity.
tat2z_21
tat2z_21
The reason that a white LED has a spike in the blue range is because, the LED uses the blue phosphorus to excite the rest of the color spectrum. This would be the reason for the spike in the 450nm range.
Yea that would make sence. To be honest from some of the testing I have done/seen I have no dought that Led's can match t5's, vho's and MH (up to 400 watts) in terms of par and even intencity. What worries me is the statements made (the first quotes) above. I would like to see some results that show that. I have plenty of spectral analysis charts I am just trying to line up the same in terms to LED so I can look at them. Check the link I gave for lighting and corals, you will find some charts, if I can get the same, under the same measures then we are comparing apples to aplles.
Mojo
tat2z_21
tat2z_21
http://apps1.eere.energy.gov/buildings/publications/pdfs/ssl/lifetime_white_leds_aug16_r1.pdf
All electric light sources experience a decrease in the amount of light they emit over time, a
process known as lumen depreciation. Incandescent filaments evaporate over time and the
tungsten particles collect on the bulb wall. This typically results in 10-15% depreciation
compared to initial lumen output over the 1,000 hour life of an incandescent lamp.
In fluorescent lamps, photochemical degradation of the phosphor coating and
accumulation of light-absorbing deposits cause lumen depreciation. Compact fluorescent
lamps (CFLs) generally lose no more than 20% of initial lumens over their 10,000 hour
life. High-quality linear fluorescent lamps (T8 and T5) using rare earth phosphors will
lose only about 5% of initial lumens at 20,000 hours of operation.
The primary cause of LED lumen depreciation is heat generated at the LED junction.
LEDs do not emit heat as infrared radiation (IR), so the heat must be removed from
the device by conduction or convection. Without adequate heat sinking or ventilation,
the device temperature will rise, resulting in lower light output.
While the effects of short-term exposure to high temperatures can be reversed, continuous high temperature
operation will cause permanent reduction in light output. LEDs continue to operate even
after their light output has decreased to very low levels.
To provide an appropriate measure of useful life of an LED, a level of acceptable lumen
depreciation must be chosen. At what point is the light level no longer meeting the needs
of the application? The answer may differ depending on the application of the product.
For a common application such as general lighting in an office environment, research
has shown that the majority of occupants in a space will accept light level reductions of
up to 30% with little notice, particularly if the reduction is gradual.1 Therefore a level
of 70% of initial light level could be considered an appropriate threshold of useful life
for general lighting. Based on this research, the Alliance for Solid State Illumination
Systems and Technologies (ASSIST), a group led by the Lighting Research Center (LRC),
All electric light sources experience a decrease in the amount of light they emit over time, a
process known as lumen depreciation. Incandescent filaments evaporate over time and the
tungsten particles collect on the bulb wall. This typically results in 10-15% depreciation
compared to initial lumen output over the 1,000 hour life of an incandescent lamp.
In fluorescent lamps, photochemical degradation of the phosphor coating and
accumulation of light-absorbing deposits cause lumen depreciation. Compact fluorescent
lamps (CFLs) generally lose no more than 20% of initial lumens over their 10,000 hour
life. High-quality linear fluorescent lamps (T8 and T5) using rare earth phosphors will
lose only about 5% of initial lumens at 20,000 hours of operation.
The primary cause of LED lumen depreciation is heat generated at the LED junction.
LEDs do not emit heat as infrared radiation (IR), so the heat must be removed from
the device by conduction or convection. Without adequate heat sinking or ventilation,
the device temperature will rise, resulting in lower light output.
While the effects of short-term exposure to high temperatures can be reversed, continuous high temperature
operation will cause permanent reduction in light output. LEDs continue to operate even
after their light output has decreased to very low levels.
To provide an appropriate measure of useful life of an LED, a level of acceptable lumen
depreciation must be chosen. At what point is the light level no longer meeting the needs
of the application? The answer may differ depending on the application of the product.
For a common application such as general lighting in an office environment, research
has shown that the majority of occupants in a space will accept light level reductions of
up to 30% with little notice, particularly if the reduction is gradual.1 Therefore a level
of 70% of initial light level could be considered an appropriate threshold of useful life
for general lighting. Based on this research, the Alliance for Solid State Illumination
Systems and Technologies (ASSIST), a group led by the Lighting Research Center (LRC),
tat2z_21
tat2z_21
Ok Floyd dont go all technical on me now. I with you on almost everything, what I am trying to figure out is the statements made by Seth and Skimmy, which are saying that their is to much intencity in the the lower spectrum that corals use for photo. They are saying that their is some evidence that folks have harmed their corals by not taking a slow acclimation to them. In my world that applies to MH also. SO what I want to do is to a spectral graph from say 400 watt mh's and line it up to a similar led so I can physically see if the photons being produce are both in a good zone and if their is somekind of weird thing going on with the amount of photons being pumped out of the LED in that range.
So here is a spectral on all 400 watt MH bulbs, find me one that uses the same side bar measures and then I can do a comparison??
So here is a spectral on all 400 watt MH bulbs, find me one that uses the same side bar measures and then I can do a comparison??
