Why actinic?

[uaru]

In nature blue light is very important because most light is absorbed already at depths as low as 1M(3ft). The blue light can go much deeper before it is absorbed. Up to 200M(70ft) if im not mistaking - thats why the ocean is blue.

Why should anyone, for any reason, use actinic light in a nano? Because of the sweet colors that everything gets from the light, or because corals actually need the blue light?

Thank you in advance. :)

[mswt5]

Because the corals need the blue light. Thats the color light they get in the ocean at the depth they are naturally found. And it looks cool....:)

[uaru]

I'm not sure if you're right. If the corals was located at a lower deepth, the corals would also use the other colors of light. If corals need the blue color, then why use 10.000K+ or any other light than blue at all?

[uaru]

off topic -

Why doesnt my pic show in the reply all of suden???

[MacnReef]

uaru,
actually, the reason we use a blue spectrum bulb is because a lot of corals are gatered from depths of 20 feet or more, unless you are talking about clams and acros! So the blue light is required by those corals to grow! Also, with daylight bulbs the blue color is just not there, even with 10K.

Also, actinics bring out colors to enhance the look of our aquariums. Have you ever seen a reef aquarium without actinics? I know I haven't or if I have, I don't remember. They are not as impressive!

[uaru]

MacnReef,

I've seen plenty of tanks without actinics, and they look great also. Just take a look at http://reefkeeping.com/issues/2002-07/totm/index.htm - IMO it looks more real than most actinic led tanks I've seen to date.

I've seen alot of people who grow corals commercially, and it's only a few of them who uses actinic.

Ive read alot of books on the topic, and I'm not sure that the actinic is for any other use than nice colors. If our tanks were 20ft+ deep it would give sence to use actinics since the other colors of light wouldnt go to that depth. But in our small tank, it doesn't make any scientifically sence to use actinic - excpet for the color of appearence of course. :)

[Nitelife]

I may be off here but the link you supplied states that they were useing 10,000K bulbs.......Don't they provide alot of blue compared to 6500K?????So it may not be full actinc,but it is getting sum blue.???????/

[uaru]

Nitelife:

That's my point exactly. We don't need actinic on nano's when we got 10.000K bulps. :o) The only reason I can see for use of actinic, is the color, and IMHO I don't like the blue "ghost" color the fish and corals gets when lit by actinic.

If you take a look at Lunchbuckets 20G reef, it looks - IMO - like a ghost tank. He's got a 20.000K HQI and 2 PC actinic. It looks very stange to my me. Not natural at all.

I'll only use 2 10.000K flourescent tubes on my next 10G nano. I'll post some pics when it's up and running, which should be within the next two weeks.

[MacnReef]

Ok, here it goes......Like nitelife said, he uses a 10K bulb. I am sure if cameron could fit it, he would use an 03 for dawn to dusk effect. If I were you, I would use one 03 tube and one daylight bulb. This way you can dawn to dusk and you will get the same spectrum as using two 10K bulbs.

Do you understand that it is very shocking for corals when the lights just "shut off"?

Here is a question for you...Why wouldn't you use actinics. Water is blue-er the deeper it gets because the yellow and white fades out in the ocean. So if a coral is gathered from 20ft and put under only daylight bulbs, it is not getting an adequate spectrum. Also, you mentioned that you have seen a lot of people grow corals commercially, well if you notice they are prolly growing sps or clams...Which are shallow water corals! If you go to a local guy, www.thelogicalreef.com, you will see that he uses pc that are 50/50. Half blue half white. More natural to most corals that are not acros and other sps!

[MacnReef]

Using actinics or not using actinics is "PREFERENCE"! This is always going to be debated but who cares!

[KorbinDallas]

Here's something that's gonna bake your noodle:

Dusk and dawn mean the sun is lower in the sky, so the incident light on the water's surface is at more of an angle. Most of the blue light is reflected when it hits the water's surface at an angle, and the red/orange/yellow light penetrates until the sun is higher in the sky.
At least that's what I gathered from MKramer on nano-reef.com.

Until further notice, I am turning my 67000K white lighs on first for my dusk/dawn :spin2:

[MacnReef]

What are you talking about?

The sun is not what produces the blue light! It is the hydrogen molecules in the ocean...the more molecules(the deeper) the blue-er. DER

[uaru]

KorbinDallas:

Are you sure you got 67.000K bulps ???

[MacnReef]

DUH, HE means 6700K

[uaru]

Macnreef:

>The sun is not what produces the blue light! It is the hydrogen molecules in the ocean...the more molecules(the deeper) the blue-er.<

Thats not correct. Hydrogen molecules dont produce any light at all. (i quote from Baench Marine Atlas Vol. 1 page 112) "The blue light is not absorbed as rapidly as other wavelenghts, which explains why everything in the sea appears blue-gray, even in shallow water". (page 124) "Blue light (actinic), with its wavelengths of aprox. 400 to 450nm, is an important growth factor for deep-water invertabrates."

And since there are only blue light at larger depths, we shouldnt have any other colors than blue in our tanks - in theory.

This scheme is taken from the same book:

Color / Depth of which light is totally absorbed:
IR / 0.7 meters
Red / 1.3 meters
Orange / 17 meters
Yellow / 30 meters
Blue / 450 meters
Violet / 35 meters
UV / 1 meter

Since i have great confidence in what the german reefkeper Hans A. Baensch writes(he's got more than 40 years fo experience!!!) I have to come to that conclusion that actinic light is not a "must-have" for a small reefs, but a "can-have" if you like the ghost appearence that actinic blue lit tanks can have.

One really good thing about the actinic lights though, is that you can leave it on at night, so you can watch your "nightshift" tank inhabitants. :o)

[MacnReef]

You are correct, molecules do not produce light!

But I think you are interpreting that incorrectly!

Anyways, then don't use actinic! What is you reason for this thread? Actinics are preference! If you don't like actinics, DON'T USE THEM!

[uaru]

Macnreef:

My intention was to get any input that would talk in favour for actinic scientifically, and im still hoping to get an answer for that. :)

[KorbinDallas]

I like the way my coral looks with the blue light :)

I nominate Uaru to do an experiment to determine what type of light corals do best under.

One tank all blue, one tank all actinic, one tank all white, one tank all red, and one tank with no light as a control. Has this ever been done? All the debate I see over actinic lighting, it seems like someone would have already done this at one point.

[MacnReef]

Ofcourse, it has been done. That is why 6500K Iwasaki, is the bulb of choice for most reefers with large tanks! I can't remember but one time I had seen a guy that had done an experiment. But I would think it would be hard. I mean you could have to brains that look identical but who knows where they come from. One could be from a deeper part of the ocean or tank raised or even under a cliff in the ocean. So a coral that has been in the shade for most of its life will not like direct lighting by metal halide and a coral that has been on a reef lagoon, will not like the actinics!

Who knows, it would be nice if someone had two corals in two similar tanks with the same parameter with opposite lighting and see which one grows best!

[uaru]

KorbinDallas:

As said. In about 2 weeks or so, I get my new 10G tank up with only 2x15W 10.000 flourescent tubes. All my corals are at this point of time in a 7G tank with only one 15W 10.000K tube, and they grow and expand like crasy. :)

I'll post the pics on the nanoreef board when I've set up the new tank. Im gonna move into a new aparment in the center of my town this weekend, and as soon is I've done the painting and decorating of my apartment, I'll set up the tank. :)

Thank you all for this nice little debate on actinic. Always a pleasure to talk nanoreef on the board. :)

[blulegend]

I think you will be fine with just 10KK. I had 2 10KK bulbs and for dawn/dusk, I just had 1 go on at dawn, the other go off at dusk. That way it also "kinda" (extremely, kinda) seems like the light is moving like the sun. But not anymore. I have 250W MH now.

[mswt5]

Each color of the spectrum slow disappears as you go deeper into the water. Starting with the red end of the spectrum and going to blue. Scientific fact!! Oh yeah.....THE SUN PRODUCES FULL SPECTRUM and more!! If it didnt you wouldnt be able to see all of the different color you see when you are outside. When you see a person wearing a red sweater outside its because the sweater is absorbing all of the other colors of the spectrum and bouncing the red color back at your eyes. Plants are green because they absorb mainly the blue and red color and bouce back green.

Actinic lights also produce waves(actinic 03) that are out of our eyes range of sight. Other lights may not produce those or not enough of this. That is the PRIMARY reason we use actinics. If you had a MH that produce less of this part of the spectrum than an actinic NO it would however put out enough of this part because of the wattage(brightness).

[edying]

Hey folks -

You may all may want to take a look at this thread on the Dr Ron forum:

http://archive.reefcentral.com/forums/showthread.php?s=&threadid=150714

Goes into some detail on the interaction between light and corals and yes, there is some arguement about +/- of certain types of bulbs such as the saki's versus radiums.

-Ed

[MacnReef]

EDY,
man them people are smart! I can barely some of that! Anyways, thanx for bringing that thread to my attention!

[MacnReef]

I can barely some of that

What I mean't to say was, I can barely understand some of that!

[spineshank385]

Originally posted by MacnReef


Do you understand that it is very shocking for corals when the lights just "shut off"?



actually, corals cant really tell....the dusk/dawn period of actinics is more visual. I remember reading it in anthony calfo's Book of Coral Propagation. Anthony says that the coral benefit much more from a steady, consistent photoperiod.

The corals dont really notice the shock, it is more the fish and inverts that are scared when the lights suddenly shut off.

[MacnReef]

Well, I can tell you that I was trying to grow xenia in a tank and had 4-96W pc all on one timer...I could not get them to grow and actually I had some die off. I picked up another timer and proceeded to have a "dusk to dawn" effect and ALL of my corals, especially the xenia grow like crazy! I changed nothing buy the timers!

This is just my own personal experience!