Refugium Bulb

[Bryan]

Anybody seen this bulb locally at the Home Depot or Revy?

http://reefcentral.com/forums/showth...hreadid=313318

[Beverly]

Bryan,

I read the text that went along with the package of the bulb. It's rated at 5100K. Personally, I wouldn't use anything under 5500K, with 6500K being considered very close to daylight. But it looks cheap enough to give it a try. Let us know how it works out if you find it and use it.

[DOO-E]

As a matter of fact we are running our hole house with those bubls they save alot of energy. But they are dimmer at first when you turn them on then over an hour they get brighter.

[Beverly]

Originally Posted by DOO-E

As a matter of fact we are running our hole house with those bubls they save alot of energy. But they are dimmer at first when you turn them on then over an hour they get brighter.

Yes, they are great for general household use, but maybe not so great for use in a refug because of the lower Kelvin rating.

[DOO-E]

I agree i would go out and get myself a POWERGLO for the LFS and use a couple of those.

[Bert]

The last 2 times I have been to Home Depot there have been 6500k CF screw in's. I think they were 32 or 33W. You could give those a try. Before I switched to CF in my refugium I ran a 4100K 175W MH bulb, the only difference I found is that I had to clean the glass about twice as often and a brown monti frag I had down there developed purple tips and mauve base (polyps stayed brown though). Xenia grew pretty fast too.

The recomendation to use "blue" lights stems a little bit from science and a lot from observation. For the science side, there are 3 main photosynthetic pigments in a dinoflaggelate. These are chlorophlyll a, c2 and peridinin. Plants have a and c2. A is able to absorb red and blue light, reflects green (making plants green). C2 is an accesory pigment that uses blue light, it's importance is debatable. Unique to corals is peridinin, it absorbs blue/violet and makes up ~77% of the pigment in the SPS species that have been studied. So when asking the question "what kind of light do corals use" the answer is probable about 25% red and 75% blue/violet with varying amounts of green depending on the exact chlorophyll/peridinin complex. This makes your corals look brown b/c yellow and green are reflected.

The question "what makes colorful corals red/blue/green etc" Is answered by previous studies as one of 2 possiblilities- sunblock or light transfer. There comes a point when the light load is too much and the zooxanthellae shut down. This would be deadly to the coral, or would at least slow its growth, so the coral itself makes pigments to decrease the light reaching the zooxanthellae. With light transfer, there is a fair deal of physics involved but basically high energy light (UV, far violet) is useless to photosynthetic organisms. It is also the type of light that is best able to penetrate water. Corals have overcome this by producing flourescent pigments. The idea is that b/c all energy must be conserved, a coral may make a pigment that absorbs high energy light (which is useless photosynthetically) waste a little bit of energy and retransmit that light at a lower engery stage (blue, red, green etc) that is useful to the photosynthetic apparatus. This is why corals "color up" in bright light (they make pigment to protect thier zooxanthellae and prevent photoinibition of photosynthesis) this pigment may or may not be fluorescent. Some of coral "glow" because they are taking light that is useless to them and changing is to light that is usefull to them.

(wow, I didn't expect this post to be this long)
anyways to cut to the point, if you blast your corals with enough light they will color up to prevent photoinhibition provided there is enough red and blue light to cause photoinhibition (ie green light won't work). If you use blue light, you will have the benefit of coloring up (if high enough intensity to cause photoinhibition) and fluorescence (if there is enough "useless" high spectrum violet/UV to cause excitation of fluorescent pigments and the prevailing light intensity is low enough that the fluorescence is not washed out. For instance with EYE bulbs, there is enough violet to cause significant fluorescence, but it will be harder to see because of all the other light washing out the effect). With really really blue bulbs, you will have a whole lot of fluorescence because of the high UV/violet and it will be visible because the effect is not washed out by other wavelengths. This gives that "Pop" from high K lights.

The net effect is this.
-coral will grow under any color of light provided there is enough red and blue, but blue is more important. Algae doesn't like red any better than coral, but it is less able to use blue. So the net effect is that the coral may have trouble outcompeting the algae if your nutrients are high.
-Intensity will cause coloration by photoinhibition in corals that are equipped to deal with high light. Low light corals may not be able to produce enough "sunblock" pigments to prevent photoinhibition, so at first they shrivel up to prevent too much light exposure, but they may eventually die.
-Blue light has the benefit of high usability and enough far violet to cause fluorescence.
-Really blue light looks cool but is less usefull so you need more. However the corals are using flourescence they will look cool w/o producing as much sunblock pigments.

Now take into acount that color temp influences the amount of light output per certain wavelength but does not determine it (eg a 400W EYE will blow away a 400W 10000K in the blue department, but also makes alot of green and red), and that makes bulb choice a little harder (of course then there is the fact that PAR is determined from the ideal photosynthetic curve of a plant w/ only C/a and C/c2, w/o taking into account the extra use of blue by peridinin containing zooxanthellae). I guess you have to decide the level of aestetics you want and the coral growth you want and weigh them. Look at the spectrum output of each bulb and look at the amount of output in the usable range, even of the color is "off" the spectrums are most important. As was stated before, it is hard to beat an EYE for Blue and red output, so this bulb is likely the most "photosythetically usable" out there but it doesn't look blue because if the high red/green output. If you went only in HighK=better than you would miss this fact. Reef keepers have known for a long time that EYE grow corals well from experience. The question is, how low on the K scale do you have to go before the blue output drops to equal a 10000K bulb? a 20000K bulb?

If you don't have a nutrient problem, you don't care what color your refugium is, and you don't mind giving algae a bit of a head start, then I would say 4100K or 5000K would be fine. HD has a 175W mini halide unit that runs at 4100K for ~100-150 bucks. I was considering getting one of these for my refugium since it's mostly a caulerpa sump anywase.

Well, Good luck

Bert

ps. sorry for sp. mistakes etc, not going to read this one over

[Bryan]

I currently use a 6500K 95 watt bulb over my refugium and it is useless for growing macro algae. Almost as if something is missing in the spectrum. If the bulb is available locally I will give it a try

Originally Posted by Beverly

Bryan,

I read the text that went along with the package of the bulb. It's rated at 5100K. Personally, I wouldn't use anything under 5500K, with 6500K being considered very close to daylight. But it looks cheap enough to give it a try. Let us know how it works out if you find it and use it.

[Bryan]

Are you using the same bulbs as in the pics on the reefcentral thread. Did you get them at Home Depot.

Originally Posted by DOO-E

As a matter of fact we are running our hole house with those bubls they save alot of energy. But they are dimmer at first when you turn them on then over an hour they get brighter.

[Canadian Man]

I have seen Calurpa/algae grow under halogen bulbs
So when some of you say don't go any lower than 5500k for Regugiums than that's a bit of a broad statement.

[Beverly]

Originally Posted by Canadian Man

I have seen Calurpa/algae grow under halogen bulbs

We had halogen lights over our indoor goldfish pond several years back. Grew lots of microalgae, which would still utilize nutrients. Don't know the K value of those halogens or of halogens in general, though.