Advanced lighting question--spectrum, tank depths, intensity, and T5's.

[babyblues71]

I was doing a little reading on the absorption rate of certain colors once they hit the ocean. According to one web site, these were the following depths at which certain colors were absorbed…

Absorption depth

Color Depth
Red 5 m
Orange 15m
Yellow 30m
Green 60m
Blue 75m
Indigo 85m
Violet 100m

If this is, in fact true, since we obviously can’t recreate depth with our tanks since, even at 5 meters, that’s equivalent to 16.4 feet or so, should we be concentrating more on the intensity of one color over another within the shallow depths that we have? And wouldn’t it be a heck of a lot easier to do if bulb manufacturers were somehow able to give us color percentages as opposed to hard to read color charts?

For example, although I may be wrong, it looks as though, since the violet range (420NM peak?) gets absorbed at 100 meters and the blue (460NM peak?) at 75 meters, can we assume that violet packs a 33.3% more powerful punch than blue? And if we compare the blue wavelength to, as an example, the green, it seems to be 25% more powerful than green, 150% more powerful than yellow, 400% more powerful than orange, and 1,400% more powerful than red. Just playing around with a few numbers….if this was, in fact, true, and we started basing our T5 choices, as an example, on bulb intensity differences as found in the wild as opposed to “completely equal color distributions” or “1/2 and ½”, wouldn’t this make more sense in our limited tank depths? Curious---I’m sure I’ll have many people verbally wanting to blow me away on this theory, but hey, it’s just a random thought….

Brent

 

[Roadtoad]

I think it would be useful to have bulbs designed to simulate the light wavelengths present at different depths rather than doing it by kelvins. If this were possible a 30m bulb would be green blue indigo and violet at the proportions present in nature.

The problem comes from the fact that the sun has a very continuous spectrum while fluorescents and halides do not (which depends on the elements used to make the bulb). With incomplete spectra, it is hard to develop bulbs without red, orange or yellow while having sufficient green blue and etc to emulate 30m.

Look at the relationship between water depth and wavelength of each color rather than focusing on power.

 

[babyblues71]

Oh, I agree. If we could have specific bulbs available to us that would give us the correct proportions at different depths, reef keepers would have a much easier time determining what would be more beneficial for their systems. They could be called 5 meter bulbs, 10 meter bulbs 15 meter bulbs, etc., etc. and give us the correct percentage of certain wavelengths that corresponded to what was available at those depths. It might take a lot of the guesswork out if they somehow managed to be standardized like that one day. Speaking of the color spectrum, one interesting thing I did note while reading was that, according to new research, the reason we don't perceive the sky to be violet and, instead, blue, is because of the limitations of human sight as well as the way light is scattered to our "cones." In other words, since violet actually is more powerful and can, in turn, reach to lower depths than blue, the reason we see the ocean as blue might be the same reason we see the sky as blue. Because of our color limitations and the fact that light is being scattered a certain way by the environment. Which had me thinking--if this is the case, why is it, then, that when we put actinic 03's in our tanks, we can "see" the violet purplish spectrum, but in the ocean we cannot? Is it because this portion of the spectrum is scattered so much by the atmosphere, etc., but the same conditions aren't available in our tanks, which allows us to see this purplish hue when we "up" the violet portions in our tank? And, if more violet is apparent in nature, but we just can't see it because the atmosphere is messing with our limited sight capabilities, does this mean having tanks with a more purplish spectrum when compared to blue (Which, perhaps, should be second, not first) can actually be considered a good thing? I've constantly heard good things from reef keepers who used UVL's Super Actinic bulbs, which peak in the 420NM wavelength and are very purplish to look at, and now perhaps I'm beginning to see why this spectrum should be taken a closer look at. We all seem to want our tanks to "look" blue because that's how we see the ocean, but if the environment above the ocean and then "in" the ocean is messing with what is actually coming down from the sun and, in turn, messing with our human vision, perhaps we should take a second look at what spectrum color should be more prominent in our tanks.

Brent

 

[zoozimmy]

wow

 

[Roadtoad]

so you think we need to scatter the actinic photons to keep us from seeing the tank as purple?