cool MPS thats a lotta data! My orig Question was if I can leave my actinics on (like a nite light ) Its not a good idea Ive read now. Thats the light that the reef can see down deep so to it its sunlight. My next question is if coralline algae (green purple pink etc) like that wavelength to stimulate their growth. I have some nice deep red Id like to try to spark up growth with
actinic lighting
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mps9506
Well-Known Member
Sorry, yea, it's kind of way off your original topic
I just wanted to clarify why light at certain spectrum is needed.
AFA the coraline algae, I believe light at the same spectrums is needed as corals. Water quality seems to be the key however. There are many different species of crustose coraline algae and they each are adapted to grow in different conditions, different lights intensities and spectrums. the similar factor in all of them are good water quality Key in on that and it will grow.
reefsmoker
Member
Mike! that was great, I Felt like i was back in collage. Any wisdom on MHvs.VHOvs.PC Bulb Temps,Heat Radiation and heat saturation at any distances. Fancy charts or graphs that might help out a now intrigued mind after reading Excellent information you provided us with Would be studied ino the wee hours....
Im actually wondering as we speak about what reefsmoker seems to be also! About what distances can place livestock away from certain lighting... I have PC Sunpaq dual 27 watt 460/420 actinic and 10000/6500k whites. thats 54 watts between both the blues and whites. Is placing things high up on the rock (maybe 8 inches from bulbs) an issue if they are a hi light speciman?
The aspect of the light requirements or preferences of coraline algae have to do with the amount of which lighting wave length is available at what depths, and the depths at which most live rock is harvested as well as total light intensity. Seems most of the live rock now being harvested is coming from deep waters (even advertisments state that) where mainly the short wave length lighting constitute the majority of what is available. There are only a few advertisments that statetheir specific type of live rock is conming from shallow depths, and when emailed the typical reply has been a shallow depth of approximately 30 feet. As a result most of the coaraline imported grows best under that shorter wave length lighting at lower lighting intensities. IE such as blue appearing actinic lighting. There are a lot of SPS tanks out there that have a lot less coraline than more dimmly lit tanks that are often mixed reef or nearly fish only. And typically SPS dominant tanks have extremely good water conditions in comparison to mixed reef tanks and fish only tanks. It is not uncommon to see much larger and heavier deposits of coraline on the shaded sides of rocks, tank sides, back walls and the bottom of bare bottom tanks where the lighting intensities are lower than the tops of the live rock, especially those near the top of the tank. I for one frequently ask if there are any SPS growers out there with heavy coraline growth who will send ome small rock fragements or coralline scrapings to me. I provide halide lighting in all my tanks, but not at any real extreme levels, but obviously enough for decreased growth of the deep water coraline species now most commonly available. IMO
Each coral has its own unique lighting requirement where its Saturation and Photoinhibition Points are in relation to exsposure to different lighting intensities. This in general is related to the depths in which the coral originated from. As an example an Acropora gemmifera coral from Davies Reef GBR taken from a depth of 1 meter has a saturation level of Acropora cervicornis from the Atlantic at a depth of 17 meters had a saturation level of 281 and showed photo inhibition at 340. The lighting used in these tests was halide lighting at 600 umol*m^2*second (about 30,000 Lux). Even each species can come from varying depths to some good extent, so it is a lot of trial and error most of the time. The myth that SPS all like high lighting intensities is a myth, there are SPS from depths where the lighting intensity is quite low and that just wont grow for beans if placed under the most intense lighting of the upper reachs of some tanks. Some Montis are a good example of that. Julian Sprungs book Corals A quick Reference Guide often lists two or three lighting requirements (level in tank requirements) for an individual coral.
IME coralline will grow well under just about any type of lighting from intense Halides to very weak NO bulbs. I've gone from coralline covering every surface area of my tank to nearly completely disappearing from the glass/acrylic and in every case where it's subsided there was fluctuations of my parameters namely cal/alk/mag.
Craig Manoukian
Well-Known Member
Agreed those minerals are more important than the type of light with coraline algea. My 18w dayglo refugium lights produced good coraline.
The Natural Light Environment (Steve Tyree)
From the moonlite darkness of night to the daytime photoperiod, the natural light field that enters the water over a reef varies quite dramatically during the day. In summertime, light intensity reaches 60 % of its peak value for only about 6 to 7 hours at midday. Besides intensity, light also possesses a quality or color. This represents the distribution of wavelengths or energies of the individual light photons. Wavelength is extremelly important. For example, if we only had light of infrared wavelengths, the intensity would be meaningless to human eyes since we cannot percieve that color or quality of light. Corals would also not be able to use this light. A significant portion of surface sunlight actually happens to be infrared light. This light gets quickly absorbed by water as it travels into the ocean. The visible light spectrum occurs from violet light (400 nm lower end) to red light (700 nm upper end). The most intense peak area of sunlight at sea level occurs at 460 nm (blue light). There are two basic sources of light intensity at the seas surface. Direct Sunlight is light that travels directly from the sun to a particular point. Diffuse Skylight is the area of the sky that is away from the circular suns disk. It is blue when the atmosphere is clear and can be white when clouds are present. As you get closer to the suns disk, this scattered diffuse skylight becomes more intense and more white in color or quality. At high sun elevations in dry atmospheres, the minimum % of total light that is diffuse skylight is 10 %. This can reach 25 % of the total light in atmospheres that contain some humiditidy. In heavily clouded conditions diffuse skylight can become 100 % of the total light as the suns disk is completely obscured. Skylight is a greater factor at low sun elevation angles.
As light travels through seawater it can become absorbed or scattered. The combined affects of absorption and scattering is called attenuation. Light gets absorbed in seawater by the physical water itself, dissolved yellow pigments, photosynthetic biological organisms and inanimate particulate matter. Pure water is a weakly blue colored liquid due to its absorption of yellow, orange and red light. A 1 meter (3.28 feet) layer of water will absorb 35 % of light at wavelengths of 680 nm (red). Another form of absorbtion occurs from dissolved yellow pigments (gilvin) that are derived from the decomposition of plant tissue. This is why some coastal areas have green or in extreme cases brown colored water. Inanimate particulate matter (tripton) can also absorb light. Gilvin and tripton absorb more blue light than they do green or red. Phytoplankton can also absorb light primarily with their chlorophyll a pigments. Most of the areas with coral reefs have clear blue ocean water where orange, yellow and red light gets absorbed by the physical water itself. Water is acting as a filter which allows blue, violet and ultraviolet light to penetrate deeply. Dirty coastal water can severly limit the penetration of ultraviolet, violet and blue light. Radiance is a measure of direct sunlight arriving from a particular angular direction. For example, the direct sunlight from the suns disk minus diffuse skylight from the sky is a radiance measure. Irradiance would be the total light from the suns disk plus diffuse skylight. When quantifying artificial light bulbs, radiance values from the bulb should be measured. Irradiance measurements can bias the results with the reflective attributes of nearby structure.
The attenuation of light travelling through seawater changes the spectral qualities of light. This is why photometers biased to sealevel light qualities that determine foot-candles, meter-candles or lux should be avoided. Quantum based sensors give a more accurate count of photons, but do not describe the quality or spectral distribution of the light field. This can be approximated with spectroradiometers that have bandwidth resolutions of 10 to 5 nm. These meters are unfortunately very expensive. In Jamaica at a depth of 10 m (32.8 feet), red light is decreased by a factor of 100. This virtually makes it non-existant at this depth. PAR light represents the total number of light quanta in the visible part of the spectrum (400 to 700 nm). At Discovery Bay in Jamaica, a surface PAR value of 1,925 micro-Einsteins/square meter per second was measured. At a depth of 15 m (49 feet) PAR was 392 micro-E/m2s. This means that at 15 m (49 feet) depth, irradiance was ~20 % of surface irradiance. At a reef in the Great Barrier Reef, irradiance at a depth of 10 m (32.8 feet) was found to be about 24.5 % of the surface irradiance. The depth distribution of RBSC were studied at Thochu Islands in the South China Sea. Corals were rare in the shallow intertidal waters due to wave action, strong sedimentation and a moving sand substrate. The maximum RBSC species diversity occurred at depths that had 10 to 30 % of surface irradiance, which happened to be 10 (32.8 feet) to 15 m (49 feet) depths. Shallow water areas with very intense light are occupied by only a few species of corals that have a competitive edge. Greater diversity occurs in light fields with peak intensities from 200 to 600 microE/m2s. This means that intense very high shallow water PAR values should not be what the aquarist strives for if the most diverse habitat of RBSC corals is being reproduced. This explains the awesome reef tanks with only 4.5 watts per gallon of lighting. In very clear waters, light irradiance at 10 meters depth is actually about 50 % of its irradiance at 1 meter depth. This means that violet/blue/green light intensity at 10 m depth is still more than 50 % of its surface intensity.
The zooxanthellae (phytoplankton) that inhabit RBSC, utilize light collecting pigments called photorecptors. These pigments have physical limitations that affect the type and quantity of light they absorb and convert into chemical energy. There are basically two types of pigments within the zooxanthellae: chlorophyls and carotenoids. Chlorophyls a and c primarily absorb blue light, some red and little green or yellow. The carotenoids found within these algae absorb primarily blue light. Algae from low light areas absorb more of the available light field than algae from intense light fields. Almost all RBSC species are also found inhabiting the mid-depth regions where red light is basically non-existant. This means that the corals can adapt and survive without red light. A primarily blue light field with equal amounts of violet and green light is what most of the RBSC experience in nature. They are also exposed to some amounts of UV-A due to its ability to penetrate water to mid-depths. Studies of corals have found that low levels of blue light can achieve peak photosynthesis values similar to what is achieved from peak sunlight (white light). Light at wavelengths of 460 and 420 nm have also been found to enhance algae due to factors independent of photosynthesis.
Algae have a peak rate of photosynthesis that they can achieve that is called the saturation point. The more intense the light is, the earlier the saturation point is reached. What happens is that there are simply too many photons being captured and they cannot all be converted into chemical energy. Too much captured light can actually damage and photoinhibit the photosynthesis apparatus. Algae also possess the ability to adapt to changing light fields and can change their saturation points based on the health and level of adaptability achieved.
From the moonlite darkness of night to the daytime photoperiod, the natural light field that enters the water over a reef varies quite dramatically during the day. In summertime, light intensity reaches 60 % of its peak value for only about 6 to 7 hours at midday. Besides intensity, light also possesses a quality or color. This represents the distribution of wavelengths or energies of the individual light photons. Wavelength is extremelly important. For example, if we only had light of infrared wavelengths, the intensity would be meaningless to human eyes since we cannot percieve that color or quality of light. Corals would also not be able to use this light. A significant portion of surface sunlight actually happens to be infrared light. This light gets quickly absorbed by water as it travels into the ocean. The visible light spectrum occurs from violet light (400 nm lower end) to red light (700 nm upper end). The most intense peak area of sunlight at sea level occurs at 460 nm (blue light). There are two basic sources of light intensity at the seas surface. Direct Sunlight is light that travels directly from the sun to a particular point. Diffuse Skylight is the area of the sky that is away from the circular suns disk. It is blue when the atmosphere is clear and can be white when clouds are present. As you get closer to the suns disk, this scattered diffuse skylight becomes more intense and more white in color or quality. At high sun elevations in dry atmospheres, the minimum % of total light that is diffuse skylight is 10 %. This can reach 25 % of the total light in atmospheres that contain some humiditidy. In heavily clouded conditions diffuse skylight can become 100 % of the total light as the suns disk is completely obscured. Skylight is a greater factor at low sun elevation angles.
As light travels through seawater it can become absorbed or scattered. The combined affects of absorption and scattering is called attenuation. Light gets absorbed in seawater by the physical water itself, dissolved yellow pigments, photosynthetic biological organisms and inanimate particulate matter. Pure water is a weakly blue colored liquid due to its absorption of yellow, orange and red light. A 1 meter (3.28 feet) layer of water will absorb 35 % of light at wavelengths of 680 nm (red). Another form of absorbtion occurs from dissolved yellow pigments (gilvin) that are derived from the decomposition of plant tissue. This is why some coastal areas have green or in extreme cases brown colored water. Inanimate particulate matter (tripton) can also absorb light. Gilvin and tripton absorb more blue light than they do green or red. Phytoplankton can also absorb light primarily with their chlorophyll a pigments. Most of the areas with coral reefs have clear blue ocean water where orange, yellow and red light gets absorbed by the physical water itself. Water is acting as a filter which allows blue, violet and ultraviolet light to penetrate deeply. Dirty coastal water can severly limit the penetration of ultraviolet, violet and blue light. Radiance is a measure of direct sunlight arriving from a particular angular direction. For example, the direct sunlight from the suns disk minus diffuse skylight from the sky is a radiance measure. Irradiance would be the total light from the suns disk plus diffuse skylight. When quantifying artificial light bulbs, radiance values from the bulb should be measured. Irradiance measurements can bias the results with the reflective attributes of nearby structure.
The attenuation of light travelling through seawater changes the spectral qualities of light. This is why photometers biased to sealevel light qualities that determine foot-candles, meter-candles or lux should be avoided. Quantum based sensors give a more accurate count of photons, but do not describe the quality or spectral distribution of the light field. This can be approximated with spectroradiometers that have bandwidth resolutions of 10 to 5 nm. These meters are unfortunately very expensive. In Jamaica at a depth of 10 m (32.8 feet), red light is decreased by a factor of 100. This virtually makes it non-existant at this depth. PAR light represents the total number of light quanta in the visible part of the spectrum (400 to 700 nm). At Discovery Bay in Jamaica, a surface PAR value of 1,925 micro-Einsteins/square meter per second was measured. At a depth of 15 m (49 feet) PAR was 392 micro-E/m2s. This means that at 15 m (49 feet) depth, irradiance was ~20 % of surface irradiance. At a reef in the Great Barrier Reef, irradiance at a depth of 10 m (32.8 feet) was found to be about 24.5 % of the surface irradiance. The depth distribution of RBSC were studied at Thochu Islands in the South China Sea. Corals were rare in the shallow intertidal waters due to wave action, strong sedimentation and a moving sand substrate. The maximum RBSC species diversity occurred at depths that had 10 to 30 % of surface irradiance, which happened to be 10 (32.8 feet) to 15 m (49 feet) depths. Shallow water areas with very intense light are occupied by only a few species of corals that have a competitive edge. Greater diversity occurs in light fields with peak intensities from 200 to 600 microE/m2s. This means that intense very high shallow water PAR values should not be what the aquarist strives for if the most diverse habitat of RBSC corals is being reproduced. This explains the awesome reef tanks with only 4.5 watts per gallon of lighting. In very clear waters, light irradiance at 10 meters depth is actually about 50 % of its irradiance at 1 meter depth. This means that violet/blue/green light intensity at 10 m depth is still more than 50 % of its surface intensity.
The zooxanthellae (phytoplankton) that inhabit RBSC, utilize light collecting pigments called photorecptors. These pigments have physical limitations that affect the type and quantity of light they absorb and convert into chemical energy. There are basically two types of pigments within the zooxanthellae: chlorophyls and carotenoids. Chlorophyls a and c primarily absorb blue light, some red and little green or yellow. The carotenoids found within these algae absorb primarily blue light. Algae from low light areas absorb more of the available light field than algae from intense light fields. Almost all RBSC species are also found inhabiting the mid-depth regions where red light is basically non-existant. This means that the corals can adapt and survive without red light. A primarily blue light field with equal amounts of violet and green light is what most of the RBSC experience in nature. They are also exposed to some amounts of UV-A due to its ability to penetrate water to mid-depths. Studies of corals have found that low levels of blue light can achieve peak photosynthesis values similar to what is achieved from peak sunlight (white light). Light at wavelengths of 460 and 420 nm have also been found to enhance algae due to factors independent of photosynthesis.
Algae have a peak rate of photosynthesis that they can achieve that is called the saturation point. The more intense the light is, the earlier the saturation point is reached. What happens is that there are simply too many photons being captured and they cannot all be converted into chemical energy. Too much captured light can actually damage and photoinhibit the photosynthesis apparatus. Algae also possess the ability to adapt to changing light fields and can change their saturation points based on the health and level of adaptability achieved.