Atinic Lighting

[Chad]

Ok,

Can someone please settle this for me.. I have had some confusing conversations on this one.. Is atinic lighting simply for looks or is it important to the health of the corals?

Thanks

Chad

[Bob I]

Ok,

Can someone please settle this for me.. I have had some confusing conversations on this one.. Is atinic lighting simply for looks or is it important to the health of the corals?

Thanks

Chad

I could go, (and have gone) into a long explanation on why aCtinic lighting is not a necessity/ To make a long story short, aCtinic lighting is purely aesthetic. It looks good to the human eye. :rolleyes:

[Canadian Man]

It's not necessarily the actinic lighting itself that's important. It's the specific spectrum of "blue" light which corals need.

So if you use let's say a halide "iwasaki" bulb over your 50g cube tank as your only source of light. You corals would do fine. That bulb provides a full spectrum of light which contains enough "blue" spectrum for corals.

If you added some actinic supplementation to your Iwasaki bulb it would make the overall appearance of the tank seem more white and at the same time increase the "Blue" spectrum of light. It's not necessary but it may help with coral color and Coraline growth etc.etc.

So no it's not " always " necessary but it depends on the situation.

cheers

[Bob I]

Blue color is what is left when the other frequencies are filtered out as one goes deeper into the ocean. Thus logic tells us that if we supply full freqency lighting to our corals they will grow and be "happy" Remember please that corals can't "see" worth a hoot. :onfire:

[Bob I]

Blue color is what is left when the other frequencies are filtered out as one goes deeper into the ocean. Thus logic tells us that if we supply full frequency lighting to our corals they will grow and be "happy". Full frequency is 6400K at the water surface at noon in the tropics. Remember please that corals can't "see" worth a hoot because they have no eyes :onfire:

Ater saying that, guess who has actinic lights on both of his tanks.
:BIG:

[steve-s]

Actinic Lighting....Various Authors (http://www.reefs.org/library/article/actinic_lighting.html)

Cheers
Steve

[Chad]

The reason I ask is that my DIY hood may not mount the lighting I had planned.. Would you say two 10K PC lights would provide enough blue spectrum? Ove my 20g nano btw..

Chad

[EmilyB]

A larger spectrum of blue...aka actinic IS desired by some anemones (refer to Joyce Wilkerson). It is also the most esthetic part of lighting the reef for me, aside from moonlight.

[Bob I]

The reason I ask is that my DIY hood may not mount the lighting I had planned.. Would you say two 10K PC lights would provide enough blue spectrum? Ove my 20g nano btw..

Chad

Yes it would if you like the looks of it. Remember I said I have a 50/50 over my 15 gallon? I can't stand it because it is too blue, and the par is too low for my liking. So when the new 2x65W light arrives, I will try the 50/50 in it instead of the supplied actinic. I hope with the supplied 10000K, and the 50/50 it will look better.

[Chad]

Well, I planned on having two 20w atinic's along with my 2x 55w 10k PC... but turns out the 20w are a bit too long for the hood.. I really like the look of the atinic tho.. I am using a 15w one ATM... but I thought the two 20's would look better with 2 10ks...

Chad

[Bob I]

A larger spectrum of blue...aka actinic IS desired by some anemones (refer to Joyce Wilkerson). It is also the most esthetic part of lighting the reef for me, aside from moonlight.

IMO she is wrong, and can't get to me anyway :biggrin: , I feel the chloropyll just has to work harder when you only supply blue light. Now indeed over eons the corals may have adapted to these frequencies, but IMO they will do at least as well under full specrtum lighting. And we can argue until we are blue in the face, but are unlikely to be able to prove each other wrong. In the final analysis it comes down to opinion, and BTW I too like the blue lighting aesthetics wise. :mrgreen:

[EmilyB]

I wasn't talking corals Bob. Just anemones.

And over the five years that I have kept several species, they do thrive under actinic light, which would agree with Wilkerson's findings.

[Samw]

It would make sense to me that photosynthetic animals found in deeper parts of the ocean depend more on blue light.

[Bob I]

I wasn't talking corals Bob. Just anemones.

And over the five years that I have kept several species, they do thrive under actinic light, which would agree with Wilkerson's findings.

Just to satisfy my curiosity, has anyone kept them under full spectrum lighting with preferably the same PAR values. That would be the scientific method, and then the results would satisfy me. :rolleyes:

[Samw]

Under Iwasaki

http://reefcentral.com/forums/attachment.php?s=&postid=678281

3 years later under 20k

http://reefcentral.com/forums/attachment.php?s=&postid=678302

[Chad]

Its too bad I cannot see the photos..

Chad

[Samw]

Here's an interesting experiment using blue, green, yellow, and red LEDs shining on different parts of the same coral. The effect was that the red light bleached that part of the coral whereas the blue light made it turn brighter pink.

http://www.advancedaquarist.com/issues/nov2003/feature.htm

Excerpts:

On Day 28, coral fragments were again examined under the light of the dive light and filters. The area illuminated by the blue LED had strong chlorophyll red fluorescence. Normal, but not elevated, chlorophyll fluorescence was noted on the fragment illuminated by the green LED. The bleached area illuminated by the red LED remained, as it did on Day 22, apparently free of zooxanthellae and no chlorophyll fluorescence was noted.

On Day 31, a spot of pink coloration (~5 mm in diameter) was noted at the area illuminated by the blue LED (see Figure 4). Since that day, the spot has intensified in coloration but not size.

Procedure - Round Two

It was decided that the second round of the experiment would utilize only the blue and red LEDs, plus an LED producing ultraviolet radiation.

On Day 71, it was found that the coral areas under the blue LED had gained pink coloration, and the area illuminated by the red LED had lost more zooxanthellae – it had bleached (See Figures 6 and 7). No visible changes were observed within the area irradiated by the UV LED.

Discussion

The results of this experiment suggest that narrow bandwidths of essentially ‘pure’ red and blue wavelengths have profoundly different effects on zooxanthellae health and host tissue pigmentation.

It appears that red light induced bleaching in the two experiments. It is also worthy to note that bleaching was noticed on Day 22 and Day 23 of the first and second set of experiments, respectively, even when red LED lamp intensity differed by ~20%.
....

The reasons for corals’ production of a pink pigment under blue light are not as easily explained - a theory could be advanced that some corals (likely only those genetically predisposed – see Takabayashi and Hoegh-Guldberg, 1995) react to blue light by the manufacture of reflective/fluorescent pigments.

[Samw]

Its too bad I cannot see the photos..

Chad


Hm, here's the thread.

http://reefcentral.com/forums/showthread.php?s=&threadid=100040&highlight=tapetum


The pics are:

http://reefcentral.com/forums/attachment.php?s=&postid=678281

http://reefcentral.com/forums/attachment.php?s=&postid=678302

[Bob I]

There is one thing that would shoot giant holes in my argument. I am basing my argument on terrestrial Chlorophyll. If there is such a thing a aquatic chlorophyll, which reacts to blue light, my argument would not work.
If someone knows of such a thing, I would hope he/she will post it, and make this thread educational instead of just argumentative. :rolleyes:

[Samw]

Didn't the experiment just show that the red and green in the spectrum either did nothing more for the coral or bleached the coral while the blue light increased the chlorophyll?

[Bob I]

Sorry Sam, but the answer is a definite NO. The experiments although interesting did not follow the scientific method. Too much of what we take as gospel truth is based on incomplete experiments, or what seems to work for one guy. It did give some interesting hints of what may be the case. There is so much more to learn. My argument is based on FULL SPECTRUM lighting, which contains all the wavelengths equally.