Benefits of Actinic Lighting?

[DLANDINO]

I am upgrading my lighting....AGAIN...! I will be going from dual 150w 20k halides to 2 175 watt halides and 2 T5VHO actinics. I have already formed my own opinion about the possible benefits of actinic lighting but was curious about what everyone else feels their benefit/purpose is.

I have a few SPS corals in my tank whose branches sit directly under my blue led moon lights. The branches of those corals that are touched by this light are brilliantly blue in comparison to other branches of the same coral that are not in the direct path of this light. So, I am thinking that by adding actinic lamps all of my sps will receive more blue light and absorb that color.

What are your experiences and thoughts on this issue? I know that some think there is no benefit at all and it is only visually pleasing with no benefit to coral at all and those that swear by their use. Thanks in advance.

 

[pecan2phat]

There are many differing opinions on actinic supplementation. Some will tell you that in "real life", SPS corals found in shallow reef crest areas are actually all a shade of brown from the 5500k light that is projected over the area. Some will tell you that when you dive, all you see is a blue cast of light hence the actinics.
I like actinic supplements for the dawn to dusk look. I also think that it does help with the colors of corals especially blue range SPS. For a couple of years, I used XM 10k MH bulbs and it gave unparallel growth but not great blues and reds in corals. When I switched over to Aqua Connect 14k bulbs I noticed better color overall but not as great in growth. With the XM 10k bulbs, I had the VHO actinics on with the MH photo period but with the AC 14k bulbs, I only have the VHO actinics on 2 hours before and 2 hours after the MH photo period.

 

[FroMan]

The quickest answer to this is spectrum. Sun light gives off all wavelengths (in various intensities) It is very difficult to create a light bulb that gives off light evenly across the electromagnetic spectrum. You generally end up with peaks at a given wave length (i.e. 6500K). By adding various bulbs you can even out the tones of the corals and draw out the colors through blending and overlap of the peaks.

Check out the spectrum of the bulbs that reef geek has in their T5 section http://www.reefgeek.com/lighting/T5_Fluorescent/Bulbs/

Keep in mind that the color your eyes see, is the color that is NOT being absorbed by the corals. So if a coral is green, it is absorbing red, yellow, blue, indigo, and violet wavelengths.

Red light has the shortest wave lengths, violet has the shortest. When light strikes water, certain wavelengths are going to be absorbed more readily than others. The shallower the water the more broad the spectrum that is going to reach the coral. The deeper you go, the more blue the water will be due to absorption.

Most people go for the blue more than a red/yellow tone due to the corals having iridescent properties "glowing" under black light.

I think the benefit of having a blue spectrum is that you are going to give the corals more of the light they normally receive from the sun. I'm not a fan of the really blue/purple look that some people have gone for. I think it is a bit much and detracts from the overall scene of the tank. Conversely, it dose bring out the color of the corals.

 

[DLANDINO]

Thanks both! I have much to learn but am in the right place.

 

[mikelaubach]

So it seems there are bulbs in the 460nm and 420nm being called "actinic," at least in the power compact bulbs.

Which is really right?

I have "Super Actinic" from UVL for the VHO bulbs for the new hood, but wanted to get new PC bulbs.

 

[argi]

So it seems there are bulbs in the 460nm and 420nm being called "actinic," at least in the power compact bulbs.

Which is really right?

I have "Super Actinic" from UVL for the VHO bulbs for the new hood, but wanted to get new PC bulbs.

460nm are a more blue light, brighter in color and are also sometimes called 7100K bulbs. 420nm is a more purplish color and aren't as bright bt really help to fluoresce corals more.

 

[mikelaubach]

Thanks Keith, they have 420/460 bulbs, so I guess that'll give the best of both worlds.

I made $150 selling an old 5-speed transmission tonight. Of course, that's already gone for my two 250W XM bulbs and an actinic PC bulb. :lmao:

 

[argi]

If you have never used a 420/460 bulb don't be surprised when you turn it on if it looks like the 420nm side isn't on. The 460nm is so much brighter it makes it look like the 420nm side isn't working.

 

[pecan2phat]

IMO, PC and T5 true actinics (420nm) are not worth the bulb space.

 

[FroMan]

For more on the topic, check out reefkeeping magazine several good areticles there.

http://reefkeeping.com/issues/subject/lighting.php

 

[argi]

IMO, PC and T5 true actinics (420nm) are not worth the bulb space.

May I ask why?

Back many years ago I had a PC lit tank that had 10K/7100K bulbs over it. The corals did fine, but the color was not great. I switched to 10K/420nm (true actinics) and my corals lit up, nice greens and reds starting fluorescing from the corals. The color was so much better than with true actinics.

Now if we are talking metal halide lit tanks and you are using a bulb with a high K rating, yes I will kind of agree with you but if you are using 10K bulbs or less I would recommend the true actinic bulbs.

Keith

 

[pecan2phat]

Keith,

Based on a 6-bulb T5 configuration, the 420nm true actinics were basically washed out by the rest of the bulbs. I ended up using 460nm bulbs in their place and found the bulbs closer to how the VHO super actinics looked on a tank.

 

[cato]

I am upgrading my lighting....AGAIN...! I will be going from dual 150w 20k halides to 2 175 watt halides

Hi Dave. Hey bro, I think you're wasting your $$$ going from 150w to 175w. Your gonna pay a lot more for all the new equip than youre really gonna benefit from an extra 25w. If youre gonna spend the cash go to 250w or just save your $$$ and stay with the 150's. JMO. :beer:

 

[erbgo]

hi dave. Hey bro, i think you're wasting your $$$ going from 150w to 175w. Your gonna pay a lot more for all the new equip than youre really gonna benefit from an extra 25w. If youre gonna spend the cash go to 250w or just save your $$$ and stay with the 150's. Jmo. :beer:

+++111

 

[DLANDINO]

+++111

cei

I guys, heres my thinking. I am not looking to up my wattage to 175 from 150 but I am looking to add the benefit of the actinic bulbs. The sunrise, sun set and the additional blue color is really what is driving this. This fixture is only 8.5" wide and seems to be the only fixture that will fit on top of my tank. Hanging from the ceiling is out, I'm married LOL so larger fixtures are out of the question. Does anyone know of a better solution? I am confused, not hard to do lately! Thanks again all and I look forward to continuing the discussion.

 

[DLANDINO]

By the way, 250's are available in this model but I am worried about the corals bleaching and it being too much light over a 46 gallon tank. So, please add this thought to your comments. I CAN up to 250, but just because you can doesn't mean that you should. Thoughts....???

 

[cato]

Dave, hook up with Brian and Roman and come up to my place for a day just to hang out, enjoy an adult bevie and talk reef. :thumbsup: (too much talk to type).

 

[DLANDINO]

Dave, hook up with Brian and Roman and come up to my place for a day just to hang out, enjoy an adult bevie and talk reef. :thumbsup: (too much talk to type).

Sounds good to me Scott. Lets try and work it out. I would love to see your reef in person.

 

[argi]

By the way, 250's are available in this model but I am worried about the corals bleaching and it being too much light over a 46 gallon tank. So, please add this thought to your comments. I CAN up to 250, but just because you can doesn't mean that you should. Thoughts....???

Sounds like it is time for a tank upgrade:spin3:

 

[somdinwong]

i try to give all my corals and tank inhabitants every spectrum i can by running all different lights. the more the better