Is Blue Lighting Required? (1 Viewer)

[Guest]

I was wondering if the actinics lights were really required to help corals grow or is that just for our pleasure in viewing? If they arent would corals do fine growing in just 6500 kelvin lighting??

 

[Wildfire]

Here's my two bits:

Actinics add a lot of color to the marine species that you will find, and also add some "alternate spectrum" lighting.

As for the MH lights. I've always (okay, for the past 4 months) used MH lighting to get my whites, and then supplemented with VHO actinics. To this end I use 10K MH, and (right now) 2 x VHO 03 Actinic (soon to be 4).

I feel that this gives me the best color, and I can bring the VHOs up "earlier" and take then down "later" so that I can see the color and vibrancy in the tank (a good way to judge whether your polyps are open or closed, by the way) and have a "night light" right up until I go to bed, without the heat and intensity problems that my MH lighting provides.....

Just (again) my thoughts and meanderings.

 

[Guest]

IMO Some corals grow faster under 6500K but you might be like the way the tank look. Most acro will turn more purple under 6500K and the red & green acro will not hold it color. I am testing a tank with out actinic for the last 3 months but can't say much yet because something else went wrong with the tank, I will have to wait to see resolve later.

 

[Guest]

Well i wanted to do some testing too, try to grow some frags under just 6500k lighting to see if they would grow the same without the actinics. Didnt know if actinics provided some kind of lighting that corals needed.

 

[Guest]

for those who think

For those who think I am full of it, I will keep it short

I use a 65k bulb with two 20 watt NO as dusk and dawn.....
The 65k from Iwaskai have been noted as having the best or one of the best CRI last I checked
I keep sps under it, and they grow quite well, and I have blue, purple, and red tips on acros with this lighting. And my pink birdsnest is bright pink right under bulb, and red aways further from the hotspot. (two different peices)
A higher kelvin bulb will give you better coloration on sps, but growth is not always as productive as with the 65 k
I swear by the 65k iwasaki's due to being able to make them last well over a year (18 months for me) (and they are about 60 bucks each) and still getting good growth results with them. Most 10-20k bulbs shift in color after 9-12 months, and should be replaced.(they are usaually a little more expensive, up to twice as much at times)
These are my opinions...if anyone disagrees please help the original poster out.

 

[jamesw]

"Actinic" is a flourescent type of lamp, and does not provide a full spectrum of light. These lamps put out spikes of light in narrow peaks depending on the phosphors that are used in the lamps.

MH - whether it be 6500K or 10,000K put out a broadband light that covers literally the whole spectrum.

If you'd like to learn more about this, check out Dr. Sanjay Joshi's articles at www.advancedaquarist.com - hit the archives.

For coral growth, it doesn't matter if you use 10,000 or 6,500, but the 10,000k lamps don't last as long as the Iwasaki's.

Cheers
James

 

[jamesw]

Here's a directly relevant article by Dana Riddle:

http://www.advancedaquarist.com/issues/feb2002/Feature.htm

and here's Joshi's:

http://www.advancedaquarist.com/issues/oct2002/feature.htm

Cheers
James

 

[Guest]

Thanks all for info, will read the articles...

 

[Guest]

The reason actinics are used is because of the light filtering effects of water. The blue spectrum of light is the last color to get filtered out, so it penetrates the water deepest, meaning corals receive a strong amout of blue spectrum in the wild. So, using actinics helps increase the blue spectrum that your corals need. Actinics are needed more by deeper water corals than shallow water corals.

 

[jamesw]

I think mostly the reason actinics are used is that people like the way their tanks look under actinics...

Cheers
James

 

[Cakepro]

...and to make the neighbors wonder what it is that you do late at night when the front of your house has nothing but blue light coming out of it.

~ Sherri

 

[Guest]

Exactly - the whole front of our house glows blue/purple at night. The neighbors probably think I'm growing pot or something.