Does the "color temp" affect coral growth?

[SINNERMF]

Does the color temp of a bulb (degrees Kalvin) affect any or all coral growth? I've heard wattage does, but I was curious about this subject. Any and all input please.
Thanks,
Mike

[BangkokMatt]

It

[BangkokMatt]

It is considered that kelvin and par have the greatest effect on coral growth. A general rule is - the lower the k the better the growth. The higher the k the better the colors.
Par is different between brands of bulbs (with different ballasts)but generally the lower the k the higher the par.

[reef / aholic]

http://www.personal.psu.edu/sbj4/aquarium/articles/Photosynthesis.htm

[shelburn61]

<a href=showthread.php?s=&postid=10972177#post10972177 target=_blank>Originally posted</a> by BangkokMatt
It is considered that kelvin and par have the greatest effect on coral growth. A general rule is - the lower the k the better the growth. The higher the k the better the colors.
Par is different between brands of bulbs (with different ballasts)but generally the lower the k the higher the par.

I think people tend to consider lower K bulbs better for growth ONLY because they generally produce more PAR than higher K bulbs of the same wattage. Not sure if this is what Matt meant?

I'm not sure anyone has reliable data on growth rates from corals grown under lighting of equal intensity and different spectrum?

[BangkokMatt]

That is what I meant but the rule cannot be generalised easily due to the fact that a 10k bulb from one manufacturer will be different than a 10k from another manufacturer.
It is hard to gather data on coral growth from lighting as so many other factors come into play other than lights.

[LegendLand]

im interested in finding out myself, i heard & seen that 14k can give better color, but it seems that 10k gives better growth, i have no proof, but thats how i have seen it.

[bureau13]

Check out Sanjay's bulb tests and compare PAR numbers (well, PPFD...I used to know the difference but forgot, but its the same general idea). Its in the sticky at the top of the equipment forum. I too have not seen any testing to indicate that different spectra with equivalent PAR makes any difference in growth. Personally, I would think you should try to identify the bulb/ballast/reflector combo choices that give you enough for the growth and health that you need, and then from those choices pick the color temps that you prefer (this is tricky though because its impossible to tell from pictures on the internet, color can also be influenced by supplemental lighting, and many other factors can influence coral colors, such as feeding and water quality). Also...do keep in mind that if you have a color temp that is perfect aesthetically for you, but it doesn't put out enough PAR for the corals you have, they may turn a color that you don't care for despite your aesthetically pleasing bulb color, i.e. brown.

jds

[bureau13]

Check out Sanjay's bulb tests and compare PAR numbers (well, PPFD...I used to know the difference but forgot, but its the same general idea). Its in the sticky at the top of the equipment forum. I too have not seen any testing to indicate that different spectra with equivalent PAR makes any difference in growth. Personally, I would think you should try to identify the bulb/ballast/reflector combo choices that give you enough for the growth and health that you need, and then from those choices pick the color temps that you prefer (this is tricky though because its impossible to tell from pictures on the internet, color can also be influenced by supplemental lighting, and many other factors can influence coral colors, such as feeding and water quality). Also...do keep in mind that if you have a color temp that is perfect aesthetically for you, but it doesn't put out enough PAR for the corals you have, they may turn a color that you don't care for despite your aesthetically pleasing bulb color, i.e. brown.

jds

[SINNERMF]

Do most 10k bulbs have a yellow appearance?

[barbra]

<a href=showthread.php?s=&postid=10976350#post10976350 target=_blank>Originally posted</a> by SINNERMF
Do most 10k bulbs have a yellow appearance?

10k is not very yellow compared to 5 or 6k, but it has to do with the entire setup as well. I have heard of some people getting different results when switching between brands with the same color temp (K rating), although I doubt it's a large difference.

[SINNERMF]

Are double ended bulbs "stronger" than mogul(screw in)?

[shelburn61]

<a href=showthread.php?s=&postid=10976350#post10976350 target=_blank>Originally posted</a> by SINNERMF
Do most 10k bulbs have a yellow appearance?

There is a huge difference in the appearance of various 10k bulbs. Just because a company assigns a "10k" rating to its bulb does not make it so. Bulbs also run at different colors on different ballasts.

[bureau13]

I have no idea where manufacturers get their "color temp" ratings. My AB 10K bulbs that I used to have were too yellow in my system (water clarity can impact this of course) and in fact measured at less than 8-9K in Sanjay's testing. My current Phoenix 14K bulbs are off-the-chart blue, although I'm not sure how high his measurements can reliably go.

jds