# Which 'K'?



## kakkoii (Jan 18, 2008)

what kelvin rating should I use? 5500k, 6500k, 10000k??????

something better?


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## trenac (Jul 16, 2004)

You can use any of the ones listed or a combo of those. It really depends on the color your looking to be omitted. The lower the K, the more yellow light omitted. The higher the K, the bluer the light. I personally like the 6500/6700k rated bulbs. Which to me is a white/yellowish light. In my experience 10000K bulbs tend to cause BBA growth.


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## kakkoii (Jan 18, 2008)

well I want something in the green range what would that be?


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## MatPat (Mar 22, 2004)

Take a look at this thread it should give you a good idea of what plants will look like under various lighting temps.


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## reefcrawler (Dec 31, 2007)

kakkoii said:


> well I want something in the green range what would that be?


Around 5500K range will fall you into more yellow(green) range, but 6700K is most popular in planted tank, I use 5500K MH though.


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## kakkoii (Jan 18, 2008)

what about 8000k, or a mix of 8000k and 10000k, or a mix of 6700k and 8000k?


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## reefcrawler (Dec 31, 2007)

kakkoii said:


> what about 8000k, or a mix of 8000k and 10000k, or a mix of 6700k and 8000k?


hoho, this is fun, usually the surface on earth receive around 5500K (more yellow color), this should be best growing range for plants, but in our tank, it may turn out too yellow (but I like it, it just personal flavor), as I understand, most people like to setup 6700~10000k so can get more whitish tone to simulate strong sunglinght in nature.

mix different K just a experiment to match your personal flavor, just like some people in reef tank - like to mix 10000K(white) with actinic light (blue light) to simlute the bule hue tone under the sea.

I'm not sure the exact depth, but over 60~80 ft under sea, only blue color can penetrate the water, that explains why the ocean is blue, and most shallow lake show green color... this is the light factor, of couse there're some other factors will affect the water color.

lower K - more yellow. warm color.
higher K - more blue, cold color.
6700~10000K is about the white range K

Sorry about my plain english, sound be snounds more interesting subject, hope this can explain some ideas, have fun to make different experiments.


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## kakkoii (Jan 18, 2008)

does anyone know of a *24W t5 HO light bulb* that gives off a pinkish tone?


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## MatPat (Mar 22, 2004)

kakkoii said:


> does anyone know of a *24W t5 HO light bulb* that gives off a pinkish tone?


Not as of yet. I have been waiting the manufacturers to come out with something in the 8000K range before I even think of switching over to T-5 lighting. There are too many "color" choices in T-8 tubes for me to switch over my lights. Sooner or later the T-5 manufacturers will catch up


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## tkos (Oct 30, 2006)

reefcrawler said:


> I'm not sure the exact depth, but over 60~80 ft under sea, only blue color can penetrate the water, that explains why the ocean is blue, and most shallow lake show green color... this is the light factor, of couse there're some other factors will affect the water color.


Actually for oceans, a lot of the colour will depend on the level of life in the water. Less life more blue. That is why the ocean's up here in the north are so green. Tons of life.


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## hoppycalif (Apr 7, 2005)

A lot of the color of the oceans is just the reflection of the sky. I have watched the Pacific Ocean in northern California quite a bit, and it will be blue if the sky is blue, or gray if it is foggy or overcast. Once you get below the surface, snorkeling for example, the color is more due to the selective absorption of the red end of the spectrum, leaving only the blue end. I'm sure there are lots of subtleties involved in this too.


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## kakkoii (Jan 18, 2008)

does anyone know if this light is good?: http://www.drsfostersmith.com/product/prod_display.cfm?c=3578+3733+13821+13827&pcatid=13827

in combination with 2-6700k bulbs and 1-10000k white bulb?


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## jeff5614 (Feb 15, 2006)

kakkoii said:


> does anyone know of a *24W t5 HO light bulb* that gives off a pinkish tone?


Hey kakkoii, Aquamedic Planta comes in that size and is supposed to be in the reddish range. I've been thinking of trying the 48" myself.

http://www.aquacave.com/planta-t5-lamps-by-aquamedic-982.html

I just realized it's the same bulb you linked.


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## AaronT (Apr 26, 2004)

jeff5614 said:


> Hey kakkoii, Aquamedic Planta comes in that size and is supposed to be in the reddish range. I've been thinking of trying the 48" myself.
> 
> http://www.aquacave.com/planta-t5-lamps-by-aquamedic-982.html
> 
> I just realized it's the same bulb you linked.


Stay away from the Aqua Medic Planta bulbs. They worked great for me and then burnt out after only 4 months of use. This was in a Tek fixture, not overdriven or anything like that. Others have had similar problems.

Giessemann's Midday bulb is the absolute best T5HO bulb for planted tanks. Even though the kelvin rating is 6,000k they don't have that hideous yellow tint to them that other "daylight" bulbs do.

If you are using T8s you can't go wrong with the Zoo Med bulbs. I've never been one to use compact flourscent so I can't really recommend one there. Not that there's anything wrong with cfs. I simply made the jump from T8 to T5.


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## imeridian (Jan 17, 2007)

Thanks for the warning about the Aqua Medic bulbs. 

Do those Giessemann Midday bulbs accentuate the reds like the 9325K bulbs do? 

I'll second the T8 Zoo Med bulbs, I use them for terrestrial plants and are quite nice.


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## AaronT (Apr 26, 2004)

Here's a picture of my tank with pure Giessmann Midday bulbs. The color balance is a tad off, but that's really close to what it looks like. It's not as accentuated as the 9325k bulbs though. If you want your light to be that "crisp," mix the Middays and Aquablues 50/50.


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## imeridian (Jan 17, 2007)

Thanks, I appreciate the follow up. I can definitely see why one would like those midday bulbs.


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## jeff5614 (Feb 15, 2006)

It may have already been mentioned in this thread, but Giesemann also makes their Aquaflora bulb for planted tanks that highlights reds. Only problem is I can't find any US dealers. I did find a Canadian dealer but shipping is as much as the cost of the bulb.

http://www.giesemann.de/64,2,,.html


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## jeff5614 (Feb 15, 2006)

Carolina Reefs sells Giesemann bulbs and is checking with their supplier on the availabilty of Aquaflora bulbs.


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## reefcrawler (Dec 31, 2007)

AaronT said:


> Here's a picture of my tank with pure Giessmann Midday bulbs. The color balance is a tad off, but that's really close to what it looks like. It's not as accentuated as the 9325k bulbs though. If you want your light to be that "crisp," mix the Middays and Aquablues 50/50.


Hey, nice tank!


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## kakkoii (Jan 18, 2008)

jeff5614 said:


> It may have already been mentioned in this thread, but Giesemann also makes their Aquaflora bulb for planted tanks that highlights reds. Only problem is I can't find any US dealers. I did find a Canadian dealer but shipping is as much as the cost of the bulb.
> 
> http://www.giesemann.de/64,2,,.html


nice find *jeff5614*!!!!!! it is almost the same as the spectrum graph that the ADA bulbs have.


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