light bulb types

[DJ]

What's do blue light bulbs do?

Are they just to look good?

[Fishfirst]

they are mainly used for the marine environment

[malawi4me2]

They can enhance the colors of your fish, and can be used in FW or SW. I run 2x96W 10,000K and 2x96W Actinic Blue bulbs on my 120g.

[Fishfirst]

really??? I thought a marine glo (blue spectrum) distorted a fishes color... I have one on my saltwater tank and I hate it... it looks so unnatural and the fishes colors are bland undernieth it.

[malawi4me2]

Is a Marine Glo the same as 03 Actinic? Lots of people use the Actinics in conjunction with 6,500-10,000K bulbs on FW tanks (especially Rift Lake cichlids). I've even seen tanks done with all 03 Actinic that look really good. It's really just a matter of personal opinion. I personally think that it makes the color of the tank look a lot more ballanced.

[DavidDoyle]

Actinic
These tubes emit light only from the blue end of the spectrum and are used in marine setups to supply the blue that is missing from normal aquarium lighting but is required by marine algae, anemones and corals. They are usually only available from specialty aquarium stores and are not cheap. They have little or no application for growing freshwater aquarium plants.

from http://www.geocities.com/CapeCanaver.../lighting.html

Color rendering index (CRI)
The color rendering index identifies the degree of color shift objects undergo when illuminated by a particular light source. In simpler terms, the CRI expresses the degree to which a light source renders the true color impression. The CRI is an index and ranges from 0 to 100. A light source having a CRI of 100 means objects illuminated by it look like they're supposed to; that is their natural color is not distorted. A light source having a very low CRI would tend to make objects appear to be a different shade or even color that they really are. An example of light with a high CRI is, obviously, sunlight. Some fluorescent tubes such as Daylight, Chroma 65 or Vita-Lite have a very high CRI. Some light sources such as Gro-Lux or sodium vapor lamps have very low CRI's.

from same source as above

A common Cool White fluorescent bulb usually has a CRI in the low 70's. That's considered "fair." CRI's below 70 are considered "poor." Note that CRI is irrelevant for marine setups when the aim is to simulate the appearance under many feet of water rather than to simulate the appearance of colors under full spectrum light. Blue actinic bulbs used on marine setups usually have a CRI in the 20's or 30's.

from http://www.ahsupply.com/bulbs.htm

Draw your own conclusions about using Actinics on fw tanks.

[malawi4me2]

After I did my water change today, I took a few pics of my tank so you can see the differences in the bulbs. The first is with only the 03 Actinics, the second is with only the 10,000K, and the third is with both. IMO, the third looks much more ballanced, not blue, but not yellow. Like I said, I think it's just a personal preference, but y'all tell me which one you think looks best.
03 Actinic only:


10,000K only:


Both sets of lights:

[Lexus]

I personally like it better with both lights...

[DavidDoyle]

Appearance is subjective. I like the middle pic the best but I would bet if you had lower K bulbs than 10,000 I would like it even more. My favorite bulbs of all are the Triton full spectrum tri-phosphors- they really make fish colors "pop" and plants like em too. The have a CRI of 91 or 92.