The difference between white and blue fluorescent tubes

[ahochan]

I just changed the tube on my tank's fluorescent light. It's a 36W double-tube, and the tube I had was white-white 10.000 K. The new one I got is one blue tube and one white tube. Besides significantly changing the appearance of the tank, I'm curious about what effect it will have on the livestock, and whether or not it has any effect on what kind of coral I will be able to keep.

 

[roka64]

What sized tank? It's just a different spectrum of light.

 

[Marc118]

The blue is mostly aesthetic, but it does promote the growth of zoax algae. Photosynthetic corals and inverts use it to feed.

 

[melosu58]

In the ocean the spectrum of light that makes it that depth of most corals is the blue spectrum. Yes if it is a very shallow coral then other parts of the spectrum might make it but blue is the predominant spectrum that makes it to the deeper corals. Marc hit it on the head.

 

[MT79]

If it's a true actinic lamp, it will provide light in the 420 nm range of the light spectrum. That is the wavelength that most easily penetrates water, and therefore is what many deeper water coral primarily receive. As a result, zooxanthellae can readily convert that light into sugars etc. to be used by the coral. It will also aid in the "pop" or fluorescence of the colors of many coral and fish. HTH

 

[ahochan]

I have no idea if its a "true actinic lamp" nor how to check if it is. My light is a pretty standard fluorescent fixture, and I got the tube at my friendly neighborhood LFS...

From the comments, I gather that at worst this new tube isn't going to make a difference, or if I'm lucky it might promote zoax growth.

 

[melosu58]

As a result, zooxanthellae can readily convert that light into sugars etc. to be used by the coral. It will also aid in the "pop" or fluorescence of the colors of many coral and fish. HTH

Here is an example if you can see the green glow in this leather.

 

[Marc118]

Good idea on the example, looks great.

Here is one of mine with both 10k/actinic and just actinic.

Sorry for the quality, but you get the idea.

 

[melosu58]

I get the idea and it looks nice