Color Temperature and growth.

[Big Goose]

Here is the question.

What is the best color temperature for coral growth?

I am running a of 15k on one side and 20k on the other ( one of my 20k failed and I plugged in a used 15k (used one month))

I visited a local reefer who has 10k lamps and his display looked great and SPSs were gorwing out of the tank.

Considering that the Color temperature of the sun is about 5500, and that gets shifted towards the blue end as it goes deeper into the ocean, what is the best Color Temp for growing corals in our captive environments?

I am considering switching out my lights again and running a set for growing (10k) and a set for viewing (15 or 20k).

Anybody have any data on what is the best K for growing?

Goose :bum:

 

[zaozao]

I have read that 10k is the best for growth.

 

[Big Goose]

5500 Kelvin is the Sun temp at noon. It get around 3500 in the afternoon during the Fall.

 

[Tomoko Schum]

According to Eric Borneman, corals don't care about color temperatures. They will grow under a variety of color temp very well as long as they get enough PAR (photosynthetically active radiation.)

Some 10K bulbs have very high PAR values, but some very low. Phoenix 14K beats out some of those low PAR 10K bulbs in the same wattage. Iwasaki 6500K is known to come with the highest PAR values but the color is very yellow. Ushio 10K is very crisp white and has a high PAR value, but unless it is combined with strong actinic blue like URI VHO bulbs, corals will look washed out.

I have tried Ushio 10K, XM20 and Phoenix and my corals grow very well and fast under any light. However, when I started limiting phosphate to such a low level (reads zero with Salifert) with GFO reactor, my SPS's and xenia noticeably slowed down. I can no longer call my pink pompom xenia my pink plague. It's a trade off since the color of SPS's are better with 0 phosphate.

Tomoko

 

[8BALL_99]

Like Tomoko said Color Temp doesn't matter much,, Except for the fact that lower Kelvin bulbs tend to have more Par. Higher Par=faster growth.. 10k bulbs tend to be the choice if your looking for fastest growth. Sure you can get lower kelvin bulbs with higer par but they are very yellow. I myself don't really like most 10k bulbs. I use 20k bulbs on all my tanks except for my seahorse tank and one frag tank.. Those both have 14k bulbs... Also fastest growth doesn't mean best color with some corals.. Some might start growing like weeds but they also might brown out. At the same time some corals get Great color under 10k and might look washed out with 20ks.. It really just comes down to you and what looks best to your eyes..

Will