LED's with respect to color of Sps corals

[asid61]

Corals don't use 670....plants and algae do.

I don't see any coral pigments or chromo proteins that benefit from that level of red. Look at the lists and tables in these two articles.

http://www.advancedaquarist.com/2012/10/aafeature

http://www.advancedaquarist.com/2012/12/corals#disqus_thread

The bleached thoughts may have come from a study that Dana Riddle performed. Under just a red led the coral was damaged. I believe that green and blue were also tested and they caused no damage. I'll try and dig the article up.

You only have to look at the huge spike of blue that most lighting systems use, to make it more pleasing to our eyes, to know that blue doesn’t damage corals at elevated levels.

The concern with the red diodes is that it’s possible certain corals placed under their tight beam could damage the coral or won’t allow it to color up correctly.

If you go back to the gold standard I’ve used at the start the 400w Radium bulb, it doesn’t have that huge red hump. Again, this thread is about coloring corals not if they can grow under certain lights.

You can see a small hump on the radium chart and that's from overdriving the bulb on a HQI ballast. It shows some red which makes the ambient look more white to our eyes, but it doesn't spike above the other humps.

See here:

Chlorohpyll A has an absorption peak from 650-670nm. While 660nm would be better, 670nm can still work.
You don't NEED it, but it is there and can help. And you shouldn't bleach out your corals under a "normal" amount of red anyway.
You should really have a lot of 430nm light for chlorophyll A. Chlorophyll b is not as populous.

The Radion chart is a good guideline for many led fixtures. The problem is that leds actually have too wide peaks for it to emulate it perfectly.

 

[Pacific Sun RD]

Its much easier to produce enough PUR from waves coming from range 420-450m than from 670nm.
It difficult to say what is 'normal' amount of red waves - and when it start to be dangerours for corals tissue.
Please find me any person who used that fixtures(with "deep red") leds on 100% power - and how many they are in that lamp(ratio to blue).
You'll see that the amount of energy emitted by these lamps in this area is negligibly small - to increase the channel capacity causes unnatural appearance aquarium - or as the result of a disco in lamps with built-in lenses.
Let us remember that we have a marine aquariums - and hardly anyone is interested in looking pink tank (unfortunately, this effect results in a combination of royal blue LEDs and 'deep red')
Please see the following spectrum (filled).
It comes from a combination of T5 lamps with seven fluorescent tubes:
ATI Blue Plus
ATI Coral +
ATI Blue Plus
ATI Actinic
ATI Blue Plus
ATI Coral Plus
ATI Blue Plus
This lamp does not emit light in the range you're talking about - and yet, hung 25cm above the water can stain (and growing) corals at a depth of 20-30cm (about 50cm from the light source).

 

[asid61]

You don't NEED it, but it is there and can help.

I never said you needed it. But I'm trying to say it is not detrimental to corals.

When I said a "normal" amount of red, I meant that you are not using red as a primary color. So if you bathe your corals in red light only, then that will harm them. But if you use something like a 3up with red, blue, and cyan for whites, and have that in a 1:3 ratio with blue, that should be okay. I run a 3up with deep red, warm white, and cyan for my whites, and 3 royal blues for my blues. That's a lot of red, and my corals aren't bleaching.

 

[Sleepingtiger]

Corals can grow under T5 and have beatifull colours? Yes.
Why -if they (T5) dont emit anything near 670nm?
Because they are getting enough energy from "low"(blue) region of spectrum.
Its like money and our pockets. If you need 100$ per day for your live - you dont have to keep them only in right pocket. You can keep 50$ in each pocket or simply 100$ in one pocket - left..
Much more important where you keep that money is how total you have to spend..

wish i had $100 bucks in my pocket.

This is great stuff... learning quite a bit. I am not happy at all with my led atm. my sps is bleaching on the tips and my aquarium water looks like there is a yellow tint to it.

 

[Sleepingtiger]

A simple white to blue ratio may not do it. There are different spectrums on the various different white LED's. Add that to the factor that there are many different blue LED's that peak at different wavelenghts and they only have a band width of 10 to nm's.

Most individuals that have fantastic results using LED's are using a combination of 4 or more different types of LED's. I personaly found a ratio of 1 420nm, 3 royal Blue 455 nm,2 true Blue 470 nm 2 neutral White (4,000K)
LED's working the best of those that I tried so far. However I would still like to add some additional light in the 490 nm range. Keep in mind that the ratio I mention is for wattage rather than just for the number of LED. As an example I run the 420 nm LED at roughly 2 watts of power each compared to the neutral whites and Royal blues that I'm running at just under 5 Watts each. The true blues are running just under 3 watts as to date noone is making a 5 or 10 watt true Blue LED to my knowledge.


Some individuals use cool white LED's so they do not need as much blue but often these individuals end up adding additional red LED's to balance out the spectrum.

can you please elaborate on your ratio? u said u are running the neutral white and the royal blues at just under 5 watts a piece. since they are rate 3 watts a piece, is that possible to run them at 5 watts?

so what do u recommend for a 90g tank as far as wattage and number of leds? thanks

 

[FlyPenFly]

The Radium 400w 20k wasn't that well known for growing coral. In fact, if you wanted fast growth, you went with a lower temp bulb.

 

[TropTrea]

Remember this thread is about LED's not Hides or T-5's.

However I'm finding that a combination of T-5's and LED's is realy the best of both worlds.

 

[D-Nak]

The Radium 400w 20k wasn't that well known for growing coral. In fact, if you wanted fast growth, you went with a lower temp bulb.

Yes, but there was a trade-off... Radiums made all of the corals looked really nice. The lower in color temp you went, the uglier the corals looked even though they grew faster.

Remember this thread is about LED's not Hides or T-5's.

However I'm finding that a combination of T-5's and LED's is realy the best of both worlds.

I completely agree. I just added a pair of T5s to my Radions and it looks a lot nicer.

The problem with LEDs is not necessarily the spectrum (it definitely can be, don't get me wrong), but how the light is delivered. Since LED output is considered "short" it doesn't travel very far, not nearly as much as halides or T5s. This is why we have shadowing issues with LEDs. There isn't enough light to hit the bottom of the tank and bounce back up to light up the undersides of the coral.

 

[asid61]

The problem with LEDs is not necessarily the spectrum (it definitely can be, don't get me wrong), but how the light is delivered. Since LED output is considered "short" it doesn't travel very far, not nearly as much as halides or T5s. This is why we have shadowing issues with LEDs. There isn't enough light to hit the bottom of the tank and bounce back up to light up the undersides of the coral.

I thought the reason was that leds are point-source, so the rocks shade the leds. The brightness is not the problem IMO; I use leds and only have shade on the lee side of the light.

 

[TropTrea]

The problem with LEDs is not necessarily the spectrum (it definitely can be, don't get me wrong), but how the light is delivered. Since LED output is considered "short" it doesn't travel very far, not nearly as much as halides or T5s. This is why we have shadowing issues with LEDs. There isn't enough light to hit the bottom of the tank and bounce back up to light up the undersides of the coral.

I will disagree here. It is a mater of evenly the LED's are distributed across the top of the tank. Each LED is a poin source so if anything blocks the rays of light nothing gets tothe other side. This is where arguements of two LED light cannons compared to 20 seperate LED's makes a big difference.

As far as short light no but LED's do have shorter band widths. What is meant here is, if a Royal Blue LED peaks out at 455 nm it is only putting out 50% of that amount of light at 450 and 460 nm, and probably producing only 10% as much at 445 and 465 nm. This is why selection to match the photosenthetic peaks is important. But minimal amount of T-5 lighting does a fantastic job of filling in most of those gaps.

 

[D-Nak]

This is going to be tough to explain, so bare with me. I think I tried to over simplify what I was trying to say, so I'll expand a bit. I don't want to derail this thread, but this all does effect the color of coral, since the undersides (not just the part in shadow, but the part that's not getting light for whatever reason) can be a lot different than the top.

Obviously LEDs are point source since they are small, especially in comparison to what we're trying to light, but keep in mind that stars are considered point source too. Being point source is an LED's blessing but also its curse. Since they're small and efficient, they're a great choice to light an aquarium. But as others have mentioned, we need a lot of them in different colors to replicate the light we need.

When I mean "short" I'm not talking about the short bandwidth of each LED. But, this is also the inherit problem with LEDs -- since a different LED is needed to cover a particular part of the full bandwidth, now we have a bunch of LEDs needed to replicate what a single halide or T5 puts out. Combine this with the need for them to be evenly spread out and we have a huge problem, since it becomes cost prohibitive to create what is essentially a panel full of LEDs, all wired separately so we can tailor the color output. Not to mention the need for lenses or optics on each LED. This is what causes the disco ball effect that many of us hate.

I think we're heading in the right direction with multichip LEDs. Once a manufacturer is able to create a powerful, efficient, multichip LED that has individually controlled color channels (since we were given the ability a long time ago we can't take it away, though it's not like we can do this with halides or T5, we just buy a different bulb), and is small enough to mount onto some sort of reflector (think lumenbright type reflector) on top so that the multichip LED faces into the reflector and the light is reflected and refracted down into the tank, then I think we'll be on to something.

 

[FlyPenFly]

Zetlight just introduced a led fixture that has two big multichips and is surrounded by smaller LEDs. Very my+t5 in style.

 

[Pacific Sun RD]

I thought the reason was that leds are point-source, so the rocks shade the leds. The brightness is not the problem IMO; I use leds and only have shade on the lee side of the light.

Right.
That effect (shadowing) not occur because T5 are linear light source - not point like metal halide or LED.
Lighwaves emitted from LED have much better polarisation than emited from T5 bulbs - so if you want to comapre them, they will penetrate deeper than from T5.

 

[DerekFF]

Right.
That effect (shadowing) not occur because T5 are linear light source - not point like metal halide or LED.
Lighwaves emitted from LED have much better polarisation than emited from T5 bulbs - so if you want to comapre them, they will penetrate deeper than from T5.

This is, and I try and tell everyone, one of the most important things about LED/halide and T5s. T5 light on top of being linear in nature can actually "bend" per say to an extent therefore creating even less shadows than halide/led. T5 create less shadows by being linear and by the type of lights produced. It's a fact. LEDs when run in a linear fashion rather than pendent style eliminate more of the shadowing issue but still not as well as T5s. Halides and LEDs can slightly overcome the shadowing downfall due to the sheer rediculous amount of light they are capable of putting out but will never be as good as T5 on the issue of shadowing.

 

[FlyPenFly]

A single t5ho bulb won't have the power and spectrum control of a quality strip light like one from buildmyled. Thinking it over, I think a center strong led as the main light such as a radion pro or vega color along with a strip at the front of the aquarium and rear will give you less shading with far more controllability and par power while beating a single t5ho fixture in shading control.

 

[DerekFF]

A single t5ho bulb won't have the power and spectrum control of a quality strip light like one from buildmyled. Thinking it over, I think a center strong led as the main light such as a radion pro or vega color along with a strip at the front of the aquarium and rear will give you less shading with far more controllability and par power while beating a single t5ho fixture in shading control.

It would do worlds better than pendant only.

 

[FlyPenFly]

I guess though there's the question of if you want to put all those things hovering over your aquarium like a science project or if you prefer the clean modern elos like aesthetic.

I've been debating it myself of modding my 8 bulb ati sunpower with LEDs for some better penetration since I have clams on the sand bed.

 

[Big E]

Wow, thanks everyone.................lots of good thoughts and opinions........keep them coming.

Nothing wrong with bringing in T5's into this thread as I believe right now it's the only way that works to satisfy both the color of acros and the look our eyes prefer in overall ambience for good coverage and spread.

It's more economical right now to add T5s at this point also than to have a large number of LED units (if they can create the correct spectrum),to hit corals from enough angles to get that full light look and color.

 

[Pacific Sun RD]

Exactly.
Or you can use ready(and nice looking) Hybrid units(LED+T5) where main light source is LED panel - and T5 are only for eliminate shadows.
if your LED panels spectrum will be correct for SPS corals - you dont need to use too many T5(using 8 bulbs of T5 and few leds dimmed is without sence - it still T5 unit with little amount of "LED" on board.

 

[Big E]

I'm confused now. We does the chart of zooanthellae light absorption show a spike in that red range? Also, according that article, zooanthellae are algae.

I guess what I think you're saying is that it doesn't affect the colorization of the coral but that wavelength is still used for energy by symbiotic zooanthellae?

Yes, zoo is algae...........dinoflagellate. They aren't the same as terrestrial plants that need more of the high range red light.

Focus more on this chart. You can see how drastically the red drops off as you get underwater.

It is used but at a much lower percentage than the other color spectrums.

Spectrum distribution at depths by Big E 52, on Flickr