Actinic Led

[jeffaquarius]

Not true. No corals prefer white light over blue, they just prefer more or less PAR. They don't know what color the light is.

Corals have senses and like the previous article says, you may have lots of PAR but may not have the right PUR (color) to satisfy a specific coral. Again PAR is a collective intensity of available PUR, whereas white sunlight is a complete mixture of colors (aka buffet).

 

[mr_X]

Corals have senses and like the previous article says, you may have lots of PAR but may not have the right PUR (color) to satisfy a specific coral. Again PAR is a collective intensity of available PUR, whereas white sunlight is a complete mixture of colors (aka buffet).

I disagree with that completely, for the reason stated below. If you have plenty of PAR, you will grow healthy corals. In the end, the color is just to make them look nice.
I have always put all sorts of corals under the same lighting and all have done fine. They do not need different colors according to what type of coral they are....they only need different intensities of the same wavelength.

Here is an article that I think is also helpful:

(The PAR/PUR of Your Reef Lights - The Importance of the PAR/PUR of Your Reef Lights - The PUR/PAR of Your Reef Lights Grows Corals)

I think I am understanding all of this. From what I am hearing PAR is the total light given while every coral has a specific need/requirement of usable light (PUR). Intensity is only a part of the lighting requirements while color from the lighting is also very important. The article sums it well with the A B and C points on the spectrum.

PAR is not total light given. PAR is the portion of light that can be used for photosynthesis. Plenty of people have grown coral under 6500k halide lamps years ago, simply because they were very high PAR, as I am now growing various corals under straight blues LEDs.

 

[jeffaquarius]

They do not need different colors according to what type of coral they are....they only need different intensities of the same wavelength.

That statement is not consistent with what you agree on the article you refer too.

Originally Posted by Schgred
Here is an article that I think is also helpful:

(The PAR/PUR of Your Reef Lights - The Importance of the PAR/PUR of Your Reef Lights - The PUR/PAR of Your Reef Lights Grows Corals)

I think I am understanding all of this. From what I am hearing PAR is the total light given while every coral has a specific need/requirement of usable light (PUR). Intensity is only a part of the lighting requirements while color from the lighting is also very important. The article sums it well with the A B and C points on the spectrum.

The final conclusion of the mentioned article.

As you can see, a light source which provides light in all three of these zones (A, B and C) is important for coral growth and health.

The 6500k or halides are just not just blues but include these 3 zones of wavelengts

 

[mr_X]

And what about the straight blue LEDs that are not full spectrum as far as internet data tells us? How am I able to grow various, colorful corals under them if I am not giving them the 3 zones? That's because this data is either incomplete, or incorrect.

 

[jeffaquarius]

And what about the straight blue LEDs that are not full spectrum as far as internet data tells us? How am I able to grow various, colorful corals under them if I am not giving them the 3 zones? That's because this data is either incomplete, or incorrect.

Here is the spectrograph of Powerchrome Blue Lagoon. The Pure Blue LED may look blue to us but they emit band of frequencies or wavelenghts that human eyes are not too sensitive to pick them up.

 

[mr_X]

I'm talking about the limited wavelengths LEDs produce. I understand that a t5 or halide will have a broader spectrum, but the LED does not according to what we read on the net. Meanwhile, lacking the 3 zones that the article says is necessary to grow corals, I can still grow corals. I would say that the 3 zone thing is incorrect, or all the data about LEDs being not full spectrum is incorrect. Which one is it?

 

[jeffaquarius]

Here is the spectrograph of the LED which is run by blues.

http://www.aquariumadvice.com/forums/f11/lighting-your-reef-best-bang-for-your-buck-239661-111.html

If you notice the tank looks blue but when we look at the graph the frequency of colors is just tapering down to all the way to red. It doesn't show spikes but they include those 3 zones we are talking about.

Edit: The pic actually it says bright white. May be we should ask JJ_MIK to give us the spectrograph with pure blue in his tank. This will give us more info on what does pure blue really emits.

 

[mr_X]

So, you are saying I am getting some red out of my blue LEDs, and that it's more than enough to grow corals even though It's extremely little?
Based on the price of that seneye unit and the fact that a basic PAR meter is double the price, I am having a hard time trusting it's results.
Anyway, let's say it's accurate. JJ-MIK is testing with both blues and whites on. How are we to know if that tiny bit of red isn't coming from the whites?

 

[jeffaquarius]

In any case, how can you explain why other reefers like Greg are not successful with just plain blue in their tank?

 

[mr_X]

I don't recall Greg ever stating that he was unsuccessful with just blues, I just think he likes the look of multi colors.
What are you proposing? That I'm not telling the truth and I'm actually using a full spectrum light source and want people to believe they are ok with just blue light? What would I have to gain?
A lot of articles on the internet are copied and pasted information. I'm only speaking from my own personal experience. Factual data.
The idea that red light is necessary for coral growth seems ridiculous to me since red is filtered out by the time you are 30 feet below the surface.

 

[Gregcoyote]

I don't recall Greg ever stating that he was unsuccessful with just blues, I just think he likes the look of multi colors.
What are you proposing? That I'm not telling the truth and I'm actually using a full spectrum light source and want people to believe they are ok with just blue light? What would I have to gain?
A lot of articles on the internet are copied and pasted information. I'm only speaking from my own personal experience. Factual data.
The idea that red light is necessary for coral growth seems ridiculous to me since red is filtered out by the time you are 30 feet below the surface.

You are correct, I like the look of broad spectrum, but never claim that it is needed for optimum growth. If you dive and have been below about 50' there are no long frequencies, at all. They have blue to work with and that's it. Only after you turn on your broad spectrum light sources when at depth do you see the corals color.

 

[jeffaquarius]

I don't recall Greg ever stating that he was unsuccessful with just blues, I just think he likes the look of multi colors.
What are you proposing? That I'm not telling the truth and I'm actually using a full spectrum light source and want people to believe they are ok with just blue light? What would I have to gain?
A lot of articles on the internet are copied and pasted information. I'm only speaking from my own personal experience. Factual data.
The idea that red light is necessary for coral growth seems ridiculous to me since red is filtered out by the time you are 30 feet below the surface.

What I am saying is that there are lots of corals that will grow only in deeper water with only blues while there are also corals that will only grow in shallow water where there is plenty of sunlight which is full spectrum. Now if you bring some corals that are only found in shallow water to deeper water and vice versa, what do you think will happen?

 

[mr_X]

What will happen is that they will brown out because there isn't enough PAR, but take that blue light down there at 30 feet or wherever, and increase it, and you'll grow any coral under it. This is what I am doing right now. Corals that grow in shallow waters don't need red and green, they just need more PAR than the deeper water ones. Put a ton of blue light over an acropora, and it will certainly grow and look great. As a matter of fact, it will look better than it would under the same amount of PAR coming from a lower K source.

 

[Gregcoyote]

What will happen is that they will brown out because there isn't enough PAR, but take that blue light down there at 30 feet or wherever, and increase it, and you'll grow any coral under it. This is what I am doing right now. Corals that grow in shallow waters don't need red and green, they just need more PAR than the deeper water ones. Put a ton of blue light over an acropora, and it will certainly grow and look great. As a matter of fact, it will look better than it would under the same amount of PAR coming from a lower K source.

How much of that is due to very short frequencies, even UV penetrating down deep enough that those corals color up to protect themselves?

 

[mr_X]

You lost me. UV penetrates how deep?

 

[Gregcoyote]

You lost me. UV penetrates how deep?

http://www.int-res.com/articles/meps/144/m144p109.pdf


UV at about 350nm penetrates surprisingly deep. And it would seem at 30' or less it contributes to some protective coloration. How do you see it working? If 455nm penetrates down deep, it would seem 350nm would penetrate as deep.

 

[mr_X]

Ok. so, explain the coloration of my corals under just the blues, allegedly at 460nm and nothing else. They look nearly as good as the ones in the main tank. The reason I say they look less colorful is the lack of PAR.

 

[Gregcoyote]

That's not what I was saying. I agree with you about PAR, I am just trying to sort out the effect, if any, short frequencies like UV have on coral color and growth. As you noted, using short blue frequencies tend to color up the coral more than the browns you get under other lighting. You think that is PAR related or the coloration of the light?

 

[mr_X]

It's certainly not UV or lack thereof. Yes, I do think PAR has a lot to do with coloration. I don't think UV has anything to do with it.
This statement "Our experiences suggest that coral coloration is a response to PAR levels, not UV. In short, we find no reason to subject reef aquaria to high UV levels. "
taken from this article-
Ultraviolet Light, Marine Aquariums and Coral Reef Aquarium Tank, Stand, Canopy, and Aquarium Filter System
backs me up.

 

[Gregcoyote]

Just asking a theoretical question as a Internet search will yield evidence towards both sides. As usual.