Kelvin ratings on bulbs

[Agnate80700]

So the lighting im currently considering is a combination VHO and MH @ 1030 watts for a 150 tank. I have the option of choosing the K value for the bulbs but I dont really know what would be optimal.

I looked in the stricky thread articles but didnt see anything.

Theres 10, 13k, 20k.... what values will do what. Any reading material would be appreciated

As far as I understand, the deeper corals like higher values, like 20k and shallower corals prefer 10 or 13k. Will this cause me to have to decide between a 'deepwater' coral tank or a 'shallowwater' tank? or can I combine lights to cover all the bases?

[Hara]

I have used everything from 10k to 20k in my tanks. I will say that IMO, there is not a big enough difference in the growth of the corals to ever affect my decision on the kelvin rating of the bulb. I now buy lighting color that suits my version of aesthetics. I prefer a bluer tank, I went to all 20k bulbs and that was TOO blue. I now run a 20k in the middle and have 13k on the outer edges. Plus the PC actinics. After many years of swapping out different combinations, this is what makes me happy.

[MT79]

6500k is sunlight. 5000 k is yellow, 20 k lighting is blue. Higher K bulbs produce less PAR, but generally give better looking colors. Less PAR means slower growth, and less water penetration. This link has performance numbers as welll as pics to see the visual difference in color.
http://www.cnidarianreef.com/lamps.cfm

[tecwzrd]

Nice link Mike Here is another link for color comparisons using MH only and MH/VHO combos.

[Agnate80700]

so lets say I went with 13k bulbs, from what I saw on those links (thanks by the way) 13k has enough blue to make it look aquatic but not too blue to blue everything out, would the 13k bulbs make anything i choose to put in the tank happy?

[MT79]

Basically, yes. Very high light animals like Crocea clams or Acropora corals, may appreciate a lower K lamp for the added intensity, but should still do well. Also reds and oranges tend to look/do better under lower K lighting. That is why I prefer a 10 k lamp for a good balance. FWIW I find 10 k Coral Vue Reeflux lamps to be a nice blue/white color- no yellow. I also use actinic VHO's for the added "pop" they give coral and fish, can't beat them IMO.

[Steven Pro]

Not all 10,000 K lamps are created equal. You really want to look at the spectral distribution. For that, check out the testing Sanjay Joshi has done here http://www.reeflightinginfo.arvixe.com/