ReeferBatman
New member
Hey guys, how are you? After posting on another thread with some of this info, I got a personal request about a thread that spelled out my collected thoughts more with data I've pulled together from many sources. So I sat down for the last hour or two to explain for everyone my thoughts on lighting in the hope that knowledge is power, and should be shared.
So without further adieu...
I have been researching intently into the lighting situation for corals in particular for the last year or so... Collected data from many many sources and have an understanding of evolutionary-biology. There was a great video (1.2 hours long!) on youtube that was a great help (where some of those pics came from) but he took it down.
To mix all my knowledge into a coherent theory...
First we must go over the terms [as they apply to us] that are often misused or interpreted - as there is no one good measure of 'light' (par is an attempt but lacks in certain areas)
Kelvin - is color to our eyes.
Nanometers (nm) - is the particular spectrum of energy delivered. (measured for our purposes of propagating corals between 300-700 nm)
Watts – only a human energy consumption measurement which is often unrelated to...
Intensity – the amount of energy delivered.
PAR (Photosynthetically Available Radiation) and PUR (Photosynthetically Usable Radiation) are simply a convenient graph for our purpose that tries its best to mix all of this data together – Par graphs do a decent job but lack some of the finer details of the other independent measurements…
but it helps as the science is so tricky and confusing to talk about… For example, if we take light with a higher Kelvin rating it means more blue ... same as the blue represented by the lower nm readings... see how easily it gets confusing?
Anyway, that's the 'science of light' and terminology in a very concise nutshell.
Now onto the biology.
As we know corals are animals and have evolved in many forms, some of which use no photosynthetic light at all for food, ranging to those which rely primarily on photosynthesis for sustenance.
First, don’t rely on what you know from terrestrial plants because they rely mostly on chlorophyll. Chlorophyll is mostly used in land plants because they have full access to the suns light… as such chlorophyll is a very fruitful strain of photosynthetic cell (it produces a lot of energy or food for the organism)… but do so it relies upon a higher [nm] peak of light… as seen here demonstrated in a par graph…
A: Phototropic response; having a tendency to move in response to light. Basically this is the Chlorophyll containing plant or algae "moving" to respond to a positive light source to begin the process of photosynthesis (initial growth of plants, zooxanthellae, etc.).
B: Photosynthetic response; the process which begins when energy from light is absorbed by proteins called photosynthetic reaction centers that contain chlorophylls.
C: Chlorophyll synthesis is the chemical reactions and pathways by the plant hormone cytokinin soon after exposure to the correct Nanometers wave length (about 670 NM) of light resulting in the formation of chlorophyll, resulting in continued growth of a plant, algae, zooxanthellae and the ability to "feed" and propagate, and without this aspect PAR (670 NM light energy), zooxanthellae and plants cannot properly "feed" propagate. The results of the lack of this high PAR "spike" would be stunted freshwater plant growth, and eventually poor coral health in reef tanks."
In other words..
A) [420-500nm] Coral wakes up and turns toward light
B) [580-650nm] Photosynthetic Cells prep for final stage
C) [ 670-700nm] Coral 'food' actually created from Chlorophyll containing photosynthetic cells.
That said, here is the natural graph of sunlight par… and how it is “filtered” out by depths…
And how the light is 'filtered' out at depths measured in PAR...
As we can see, upper nm registers (red light) are filtered out first as light travels through water. As a result, although some corals do use chlorophyll, most corals rely more heavily on other strains of photosynthetic cell in addition to or in lieu of chlorophyll.
But that is not to say that corals don’t “need” the upper registers of light… If you notice, even up to 60 feet down, the corals still have access to at least some light up to the 600nm range... this is why past about 100 feet (represented by the red line below) we find very few photosynthetic corals… because there is very little light left other than blue light left that far down.
Each coral has its own “strains” of photosynthetic cells. One strain may “create food” at 450 nm (and look green), while another strain might “create food” at 550 nm (and make the coral look more yellow/orange). Most corals have many strains... reacting to many different spectrums of light.
There are two different types of photosynthetic cells in corals, fluorescent and non-fluorescent. Non-fluorescent are just that… They absorb light at a spectrum and reflect that light back.
The other type is fluorescent. This type is really cool as it takes in light of one spectrum, and the light it gives off is of another part of the spectrum . Imagine the cell eats blue light, and spits out green light! These are most of the pigments we find so beautiful in our corals.
Anyway, many of the different “strains” of photosynthetic cells are listed below for your convenience.
For more in depth data on particular photosynthetic cell strains and their own particular activation (creates food for coral) rates, see some links below
http://www.advancedaquarist.com/2009/1/aafeature1/
and
http://www.advancedaquarist.com/2006/9/aafeature
...Continued below...
So without further adieu...
I have been researching intently into the lighting situation for corals in particular for the last year or so... Collected data from many many sources and have an understanding of evolutionary-biology. There was a great video (1.2 hours long!) on youtube that was a great help (where some of those pics came from) but he took it down.
To mix all my knowledge into a coherent theory...
First we must go over the terms [as they apply to us] that are often misused or interpreted - as there is no one good measure of 'light' (par is an attempt but lacks in certain areas)
Kelvin - is color to our eyes.
Nanometers (nm) - is the particular spectrum of energy delivered. (measured for our purposes of propagating corals between 300-700 nm)
Watts – only a human energy consumption measurement which is often unrelated to...
Intensity – the amount of energy delivered.
PAR (Photosynthetically Available Radiation) and PUR (Photosynthetically Usable Radiation) are simply a convenient graph for our purpose that tries its best to mix all of this data together – Par graphs do a decent job but lack some of the finer details of the other independent measurements…
but it helps as the science is so tricky and confusing to talk about… For example, if we take light with a higher Kelvin rating it means more blue ... same as the blue represented by the lower nm readings... see how easily it gets confusing?
Anyway, that's the 'science of light' and terminology in a very concise nutshell.
Now onto the biology.
As we know corals are animals and have evolved in many forms, some of which use no photosynthetic light at all for food, ranging to those which rely primarily on photosynthesis for sustenance.
First, don’t rely on what you know from terrestrial plants because they rely mostly on chlorophyll. Chlorophyll is mostly used in land plants because they have full access to the suns light… as such chlorophyll is a very fruitful strain of photosynthetic cell (it produces a lot of energy or food for the organism)… but do so it relies upon a higher [nm] peak of light… as seen here demonstrated in a par graph…
A: Phototropic response; having a tendency to move in response to light. Basically this is the Chlorophyll containing plant or algae "moving" to respond to a positive light source to begin the process of photosynthesis (initial growth of plants, zooxanthellae, etc.).
B: Photosynthetic response; the process which begins when energy from light is absorbed by proteins called photosynthetic reaction centers that contain chlorophylls.
C: Chlorophyll synthesis is the chemical reactions and pathways by the plant hormone cytokinin soon after exposure to the correct Nanometers wave length (about 670 NM) of light resulting in the formation of chlorophyll, resulting in continued growth of a plant, algae, zooxanthellae and the ability to "feed" and propagate, and without this aspect PAR (670 NM light energy), zooxanthellae and plants cannot properly "feed" propagate. The results of the lack of this high PAR "spike" would be stunted freshwater plant growth, and eventually poor coral health in reef tanks."
In other words..
A) [420-500nm] Coral wakes up and turns toward light
B) [580-650nm] Photosynthetic Cells prep for final stage
C) [ 670-700nm] Coral 'food' actually created from Chlorophyll containing photosynthetic cells.
That said, here is the natural graph of sunlight par… and how it is “filtered” out by depths…
And how the light is 'filtered' out at depths measured in PAR...
As we can see, upper nm registers (red light) are filtered out first as light travels through water. As a result, although some corals do use chlorophyll, most corals rely more heavily on other strains of photosynthetic cell in addition to or in lieu of chlorophyll.
But that is not to say that corals don’t “need” the upper registers of light… If you notice, even up to 60 feet down, the corals still have access to at least some light up to the 600nm range... this is why past about 100 feet (represented by the red line below) we find very few photosynthetic corals… because there is very little light left other than blue light left that far down.
Each coral has its own “strains” of photosynthetic cells. One strain may “create food” at 450 nm (and look green), while another strain might “create food” at 550 nm (and make the coral look more yellow/orange). Most corals have many strains... reacting to many different spectrums of light.
There are two different types of photosynthetic cells in corals, fluorescent and non-fluorescent. Non-fluorescent are just that… They absorb light at a spectrum and reflect that light back.
The other type is fluorescent. This type is really cool as it takes in light of one spectrum, and the light it gives off is of another part of the spectrum . Imagine the cell eats blue light, and spits out green light! These are most of the pigments we find so beautiful in our corals.
Anyway, many of the different “strains” of photosynthetic cells are listed below for your convenience.
For more in depth data on particular photosynthetic cell strains and their own particular activation (creates food for coral) rates, see some links below
http://www.advancedaquarist.com/2009/1/aafeature1/
and
http://www.advancedaquarist.com/2006/9/aafeature
...Continued below...
Last edited:
