Hi folks -

Firstly, what a pleasure it is to have such a resource as this ng. Many
thanks to all the folks who post here (and with such civility). I just
ordered some stuff to make my own pmdd based on info from this ng and
websites referenced here. What a great community.

I have a Q about color temps WRT lighting. I have a Coralife Actinic
bulb that came with the (used) hood I bought a couple years ago. It's
labeled as 7100K (FR40-T12-360-BP), and it is *BLUE* when it is on. I
still have this bulb, but I don't use it any more because it was almost
like having a blacklite in the tank - very intense blue cast. Is a
10000K bulb going to be even 'bluer' than the actinic, or is the actinic
a special kind of bulb that is just super blue in color?

The 6500K bulb (nice and white)I have now is nowhere even a tiny bit
close to the color of the 7100K actinic (BLUE), which is why I wonder if
the 'actinic' is a special kind of bulb whose to-the-human-eye color
doesn't match to the kelvin temp scale the way one would expect...

I did some searches for info about what 'actinic' is, and it almost
seems like it *is* a sort of blacklite or UV bulb meant to enhance the
colors of corals and other critters found in reef tanks. Just wondering
what some of the folks' experiences/knowledge are from this grp.

Much TIA for the help!

--
pete

"It is unwise to insult a doughnut be refusing to eat it."

I have a Q about color temps WRT lighting. I have a Coralife Actinic
bulb that came with the (used) hood I bought a couple years ago. It's
labeled as 7100K (FR40-T12-360-BP), and it is *BLUE* when it is on. I
still have this bulb, but I don't use it any more because it was almost
like having a blacklite in the tank - very intense blue cast. Is a
10000K bulb going to be even 'bluer' than the actinic, or is the actinic
a special kind of bulb that is just super blue in color?

The actinic is a special bulb. In fact, it's impossible to assign it a
Kelvin rating, because it's so monochromatic. They pulled the 7100K
number out of... well, you get the idea. It's actually pretty common for
K ratings to be anywhere from slightly fudged to completely bogus.

I did some searches for info about what 'actinic' is, and it almost
seems like it *is* a sort of blacklite or UV bulb meant to enhance the
colors of corals and other critters found in reef tanks.

Yep. Actinics produce light just below (and sometimes slightly into)
the UV range.

steve