thingss to beware of when changing to LEDs

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mojoreef

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Their have been alot of folks searching for info on things to beware of when it comes to switching from More common aquarium lights to LEDS, SO I thought we could have a little thread to explain why.

With More common lights over our tanks such as Metal Halides, Tube lighting, and so on we have to understand that they put out what is called a full spectrum lighting. So all their par (par is the light range that corals use for photosynthesis) comes out in multiple spikes. So take a look at a metal halides wave chart.


As you can see their are multiple spikes in a variety of color ranges. In this case we can see pretty decent spikes in the 400mn to 450mn zone and then again in the 525 to 600mn zone, with lots of little spike in between. Because this bulb has spikes through out the par range we call it full spectrum.

With LEDs its alot different. They put out light that is in a very narrow range across the par world. SO take a peek at a couple of led bulb types and you will see.





Ok so you can see their light output is very narrow and does not span across the full spectrum. Thus any particular LED bulb color is not full spectrum, but actuall the opposite. On a side note this is why folks that want leds fixture over their tanks should be looking for multiple colored leds to give themselves more of a full spectrum, but thats another thread, lol

Ok so what does all this mean to my coral and why am I cooking it???????

For this we have to go back to the biology of the coral. Photosynthetic corals use zooxanthellae to produce glucose (and other things) for them for growth. The zooxanthellae are basic algae that has two primary pigments that they use to complete photosynthesis. these pigments are called chlorophyll and carotenoid peridinin, these two pigments absorb light in the 425-475mn zone.

Ok stay with me now! So when you see the par of a full spectrum metal halide and then look at the charts you will see that all those photons that light bulb is putting out comes out from 400 to 700mn, some the coral will use for its zoox some that it doesnt. On an led light all of that par that it is reading is in a very narrow range and if that bulb puts it all out in the 425-475 range (which most blue and white leds do) that means that the zoox in the coral is getting all of it.

So as an example coral A under a MH with say 500par is only getting about 50% of that light in what the zoox can use. Coral B under 500par of led (blue or white) is getting about 95% of that light in what the zoox can use. Good right?? yes and no.

A bu-product of photosynthesis is the creation of oxygen, good for the tank and world but to much in the corals tissue is death. For a coral its like getting a dose of ozone right in its tissue, basically a super oxidizer which will eat tissue. So the coral has a means to fight this, what it does is release an enzyme that causes the zoox to be bailed out (ejects them) this stops the immediate threat but it leaves the coral with little or no zoox to keep it alive. In the wild it has a change as their are alot of free floating zoox in the water, but in our tanks their just isnt.

So when you change over to LEDS keep this in mind and cut your intensity down to at least half. Then slowly ramp it up over the course of a couple of months, this will allow the coral to naturally adjust the amount of zoox it has in its tissue to compensate for the increased par in the zone that the zoox use.

hope it helps


Mike
 

Scooterman

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LED's are pulse & freq. modulated to in affect change the length of the pulse on and off times to change the colors & output, now days they figured the range required to produce white light which from there they can create the ranges desired. The drivers that do this are just as important as the diode itself, It is similarly done to VFD's to control motor speed but rather light output. One thing is weird is the amount of heat needed to dissipate which is important to do also but in comparing the ratio of light output to heat they are still superior to a tube type light.
 
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1guydude

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tanks mojo! Was wondering why i burned up a birdsnest and now a milli...lol
I tried the whole dim em down thing and i think my other corals were suffering for it! I only had em dimmed down for like 3 days and the milli and birdsnest just bleach out...the milli is hopefully gonna make cuz lil bit of color is still their and the tissue on the bottom side of the branches is shadowed some wat... Stupid LEDs are awsome but dangerous... lol gotta get the whole light acclimation deal down for me darn sps!
 

tat2z_21

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Lots of good info. I do appreciate it. Kind of condenses it all into one spot for those that are researching it. Still looking at going crazy with LEDs. Thanks Mojo for putting this out there.
 

seattlereef

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Nice summary appreciate it. I would also think when introducing new coral to an LED system you should start with the corals toward the bottom of the tank and gradually move it up.
 

Skimmy

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excellent info...
something else worth mentioning is that keeping up on your iodine dosing will help the corals expell oxygen from their tissue during acclimation to LEDs.

I have been waiting for contollable rgb+uv LED fixtures, but just now barely hitting the market. now they need to get cheap... lulz
 

Krish

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Mojo...I wondered if this is something you can answer for me...

Well, here's thefirst part of it. Does a metal halide or leds put out as much par in a tank as the sun would put out on a reef about 5ft deep in the water in a country like here in the Bahamas where we aren't far from the equator, the sky is usually clear and we usually have crystal clear water with visiblity easily over 60ft? I'd say comparing to a 250W MH using a 10K XM bulb (seeing it usually has the best par) positioned about 8 inches off of the water in a tank about 12-16 inches deep.


Now the reason I ask is because I've always only had corals from out of the ocean here. Most of these came from water 5ft deep or less so they get hit pretty hard with direct light from the sun and as you know, 90% of the time, we have crystal clear water. I put these corals in my tank and I'd imagine (just assuming now) that the light a metal halide puts out (I had a 250 MH over a 38 gal and 150w MH over a 24 gal aquapod) wouldn't compare to what the sun put out on a reef at a depth of 5ft in the water at most. Is this right? If so, I was always curious why I never had any negative effects doing this. Corals grew well and never showed any negative effects being in my tank's. You usually hear about people going from one light source to something alot more intense where their corals burn if not acclimated properly etc, but what about my case? The only thing I can come up with is that being in the ocean, the corals are a lot hardier than corals most people have in their tanks. They experience extreme changes in temp, light (depending on cloud cover and how murky the water is some days when it is rough) to days where water is crystal clear and their are no clouds in the sky. Do you think being "wild" they just can take a bit more changes than say something that has always been in a tank and aren't "wild specimens (aquaculture vs aquaculture)?

Just something I always wondered. Not sure how far off base I am here... :)
 
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tat2z_21

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So just a question here since most of us are trying to simulate the perfect scenerio for our little reefs. I was reading (Yes I was reading, I know that is dangerous) but I cam across this little blurb and it made me question if adding the different color spectrums is necessary. " 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." It also went on to state "Light gets absorbed in seawater by the physical water itself, dissolved yellow pigments, photosynthetic biological organisms and inanimate particulate matter." So if this is the case would adding the reds and the greens aid in the algea growth and cause other issues. Just a question and would like to hear what you guys think. From what I read most of the corals are found 15 ft below, which at 1 meter 35% of the spectral values are already absorbed.
 

mojoreef

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Well, here's thefirst part of it. Does a metal halide or leds put out as much par in a tank as the sun would put out on a reef about 5ft deep in the water in a country like here in the Bahamas where we aren't far from the equator, the sky is usually clear and we usually have crystal clear water with visiblity easily over 60ft? I'd say comparing to a 250W MH using a 10K XM bulb (seeing it usually has the best par) positioned about 8 inches off of the water in a tank about 12-16 inches deep.
Ok its earlier and I have not had enough coffee but let me take a stab. So high noon on most reefs have a par rating of around 2000 to 2500 μEm[SUP]-2[/SUP]s[SUP]-1.
[/SUP]
[SUP]On the degradation of that as it passes through the depths a lot of things come into question, such as water clearity, turbulence and so on. But studies have shown that at about 15 feet that can be cut by as much as 45%, and at 60 feet by about 80%.
[/SUP]
[SUP]
[/SUP] put these corals in my tank and I'd imagine (just assuming now) that the light a metal halide puts out (I had a 250 MH over a 38 gal and 150w MH over a 24 gal aquapod) wouldn't compare to what the sun put out on a reef at a depth of 5ft in the water at most. Is this right? If so, I was always curious why I never had any negative effects doing this.


Your looking at the strategies the corals use in to narrow of a way. They are not static, as in they dont just sit their, they have the ability to adapt to changing conditions. In the case of SPS look at them like they are farmers, They cultivate zoox algae in order to receive their bi-product. So here is a very crude example:

Coral A has 100 zoox and their full production = 5 grams of glucose. So now you cut the light they get by 50%, so what the coral does is to allow more zoox in, or allows for it reproduce. SO now the coral has 150 zoox which at this new current level produces the same 5 grams. That makes sense?? it is early lol So we know that zoox has pigments that are green and yellow which makes brown, so when you get more of the zoox in the tissue the coral browns out to our eyes, which is also what folks see when they dont have enough light over the tank? AND then to complicate that even more, corals have other ways to compensate right?? they can slime net for food capture?? and/or they can absorb somewhat directly through tissue. So to put it all together corals have several strategies to get what they need, probably why they have been around for a bit??



[/SUP]
 

mojoreef

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So just a question here since most of us are trying to simulate the perfect scenerio for our little reefs. I was reading (Yes I was reading, I know that is dangerous) but I cam across this little blurb and it made me question if adding the different color spectrums is necessary. " 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." It also went on to state "Light gets absorbed in seawater by the physical water itself, dissolved yellow pigments, photosynthetic biological organisms and inanimate particulate matter." So if this is the case would adding the reds and the greens aid in the algea growth and cause other issues. Just a question and would like to hear what you guys think. From what I read most of the corals are found 15 ft below, which at 1 meter 35% of the spectral values are already absorbed.
Ok so you have a bunch of things going on here and are kind of looking at things from to many ways, so lets kind of set a standard and then go from their. In our reef tanks we have a whole bunch of brightly colored sps and similar, now if the natural reef your going to see mostly brown or dull colored corals, the usually brightly colored corals at depth are not even photsynthetic. So now what is that perfect scenerio we are trying to simulate is not what is perfect for the coral it is what we think is perfect (as in brightly colored). For photosynthesis the zoox in corals need mainly light in the 400-475nm zone that would make them happy, that would also make them brown! Now we want them to be blue/purple/red/green an so on right?? that would be perfect to us.

So in order to bring out the colors in coral we have to shine light waves at them that they can not directly use, from their the pigments in the corals tissue absorb those other waves of light and then shine out or flourese a usable light for the zoox. This makes that pigment dominant and thus the coral looks to our eye a nice red or purple and so on based on the light wave we are bombarding on it.

So now this can bring us back to your question of why add red and green. So green first:


So safe to say the main spike is in the 475-550nm zone?? and then Red leds



Brings light in at the 620 to 650nm zone?? So what is that going to do for us. >Yellow fluorescing pocilloporin primarily absorbs light from 440 to 520 nm and fluoresces light from 520 to 620 nm (green, yellow and orange). and >Pocilloporin primarily absorbs green/yellow (550-600 nm) light along with some upper UV-A . it emits a orange/red. So the reason I am adding them to my fixture is that I want to excite the above mentioned pigments. Or in laymens terms, the green is going to make or hold the dominance of corals that are yellow, green and orange and the Red light is going to do the same thing but will make the red and orange pigments stay dominate?? Again in the scope of overall colored LEDs in a fixture, were not talking about putting alot in, just enough to promote the various pigments to hold their dominance.

Ok Coffee run

Mike
 

tat2z_21

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I also ran across this "In nature, UV rays are filtered out by ocean water. The deeper the water, the more UV rays are filtered out of the spectrum. Since corals produce these colorful pigments as a protection from the UV rays striking them, shallow water corals have more colors: More UV, more color; Less UV, less color. " Would this also be a reason to slowly acclimate a small portion of UV in the higher range along with the other spectrums. If acclimated very slowly and not blasted could it be used in our corals to enhance the colors. I understand that without their protection from uv it can cause DNA and RNA breakdown and ultimately lead to death. But if introduced at a very low limit and slowly brought up, and obviously used speratically just like the other colors for supplemental lighting.
 

mojoreef

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Since corals produce these colorful pigments as a protection from the UV rays striking them, shallow water corals have more colors:
Most of the pigments for UV protection that corals use are actually clear. The pigments that we have been talking about (the colorful ones) are the pigments in the corals tissue that they use to change the color of light that i shining on them to a color that the zoox can us. So they absorb say red, but the zoox cant use it so the pigment fluoresces a color wave that the zoox can use. It even get deeper, you can observe what is called cross linking. So the red light comes in, one pigment will absorb it and fluoresce out a green color, but the zoox cant use it so then another pigment will absorb that green and then fluoresce out a color the zoox can use, this cross linking can go back and forth through all the spectrum s of light until it comes up with a usable one for the zoox.

And we thought we were highly developed?????


Mojo
 

tat2z_21

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Awesome, but with all other traditional lighting (CFL, METAL HALIDE(even with glass)emmiting some sort of UV and LED's producing absolutely none, should there be a small balance added to our lighting. I found a somewhere that they tested all lighting and found that all traditional reef lighting produces UV. Compact Flourescents kind of suprised me but apparently from the spark a decent amount of UV is irradiated. The test showed that even metal halides with protective glass gives 70% being transmitted through the glass above the water surface.

This is the case study.
Ultraviolet Light, Marine Aquariums and Coral Reef Aquarium Tank, Stand, Canopy, and Aquarium Filter System
 

Guerry

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Not to get away from the spectums of light but IMO anyone switching to LEDs should first test par of lighting to be removed them match these numbers with there new LEDs. The LEDs may seem dim to the eye at this point but never try to match the brightness of old lighting right out the box or you will bleach your corals. Now for those who are buying those deal of the day LED fixtures common from China at the moment your probably ok because most of those that I have par tested are producing par numbers of around 250 at 24" below fixture and have no dimming. A three watt Cree with a Carlco wide optic will produce 750 at same 24" driven at 700MA
 

mojoreef

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Awesome, but with all other traditional lighting (CFL, METAL HALIDE(even with glass)emmiting some sort of UV and LED's producing absolutely none, should there be a small balance added to our lighting. I found a somewhere that they tested all lighting and found that all traditional reef lighting produces UV. Compact Flourescents kind of suprised me but apparently from the spark a decent amount of UV is irradiated. The test showed that even metal halides with protective glass gives 70% being transmitted through the glass above the water surface.
Yes most lighting emits tiny amounts, but it doesnt change the fact that UV A or B does not have any positive effect on coral, and actual fact we no it has a negative effect, so why?? If one is looking for coloration caused by UV exposure your really not going to find it, when a coral is exposed to it will increase its MAA's to deal with it , virtually all of these pigments are clear. Just not seeing the benefit.
 

TJL

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When I first started my research on LED's 2+ years ago now could see the positives/negatives of the narrow spectrum that each emitter produced. In being able to hyper-excite certain pigments into fluorescing back the colors we like giving us even better color pop than MH lighting. When the first comercial units like Pac Sun, AI, Acan and Maxspect hit the market they all had a single blue chip 460nm-ish and a single white typically 5500-8000K with & without the ability to seperately control them. When I made contact directly with the manufacturer in China (in hopes of designing and importing my own units) and received thier catalog of over 8000 different bulb/chip/diodes in almost every spectrum realized the true potential in LED's in being able to mix in other colored chips to fluoresce a broader range of colors we like to see. Not a MH fan but have always liked the look of the Phoenix 14K lamps so am trying to emulate it in ordering my 84 @ 3w LED assortment by mixing 3 whites (5500-8k, 6500 & 10K) 3 blues (445-455nm, 450-465nm & 465-485nm) along with Cyan (500-510nm) and Red (625nm). I really should have waited to buy all my LED's since they have dropped in price quite a bit over last 15 months since I started receiveing mine. Should be back to my build soon I hope.

This is such a great thread on general LED education for all and hopefully usefull for us hobbiest as well as some manufacturers/retailers following along too.

Cheers, Todd
 

josh88

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Do any of you know of a good website that shows detail research about this. I'm getting a bit concerned now, because my jbj has a 150w 12k double ended mh in it, with 4 moon lights hitting 425 to 440 nms. And I do not want to damage any future coral I may get. And lookin at the chart Mojo showed about the mh. I feel damage could happen. I'm trying to gain a better understanding, but for my brain is not as advanced as your guys in this area. I'm finding it a but difficult to keep up

HTC tapatalk
 

tat2z_21

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I wouldnot worry about your 150w Halide over your JBJ. With it being double ended you need to make sure that you have the UV glass, and everything will be OK. Mojo was trying to point out that the LEDs are spectrum specific. Meaning that if you have all blue lights you are only betting the 450 to 460 range. Which means that the corals are getting 100 percent of the required spectrum for photosynthesis. Adding to much of this may cause issues with your corals.
 
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