# Color temp



## Grizzle Fish (May 29, 2014)

Hi folks,
I have a twin T5 fixture with a rosette and a 6000k. I'm not exactly happy with my color perception of the lighting. It's plenty bright, but has sort of a cold greeny cast to it. I believe that what I need is more yellow? Should I be looking at a 6400k to replace the 6000k to warm things up a bit? Just looks not warm enough to me if that makes sense.

Thanks for any advise,

~Grizz


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## Michael (Jul 20, 2010)

Generally, lower color temperatures look warmer, or more yellow. So if you want a warmer look, try a new tube with something like 5000K.

That said, I am not familiar with the "rosette" tube that you are using. It may be responsible for the funny colors. Try taking it out and just running the 6000K by itself. It won't be as bright of course, but you should be able to see what difference it makes in color appearance. Different people have different subjective preferences for color temperature. And it bears repeating that color temperature is NOT directly related to the amount of useful light for plants.

Personally, I like 6500K. This is a very white light, but some people feel that it is too harsh or too blue. Color perception naturally varies a lot from one person to another.


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## Grizzle Fish (May 29, 2014)

Thanks Michael,
I did a bit of reading and yes, I had it backwards as far as which direction I may need to go. The rosette is pink or redish. Unfortunately the fixture will not run with one bulb, must be wired in series, so I can't test only one. I know incandescent is somewhere around 3000k. I thought about going to Home Depot to see if they may have a lamp like that that I could pop in to test. I may not wind up with optimal plant lighting but should have enough for my application. All in all it's not a big deal, and right now the tank has no water or anything but three potted house plants in it. So perhaps once it's set up it will look much better.
Gracias,
~Grizz




Sent from my iPhone using Tapatalk


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## TropTrea (Jan 10, 2014)

One other thing to consider is that manufacturers listed color temperatures are not all the same. If you look at a color temperature chart you will see the difference between 5,00K and $6,500K is not that extreme. However there is also a CRI value that show hopw close to the true color temperature point a particular bulb is to the perfect point on the scale. General the lower the CRI number is the more color that will appear from the bulb which is why many of the higher Color Temp bulbs are usually rated at lower CRI values. Ann Standard florescent bulbs usually the 5,000K bulbs have the highest CRI numbers but one of the lowest Lumen ratings. 

Having worked for a bulb manufacturer they try to produce bulbs that the largest amount of the population will think theirs are the best. Therefore they strive for the highest Lumens possible at a particular Color temperature. Unfortunately for us green light yields the most Lumen


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## Tugg (Jul 28, 2013)

Michael said:


> ...Different people have different subjective preferences for color temperature...
> 
> Personally, I like 6500K. This is a very white light, but some people feel that it is too harsh or too blue. Color perception naturally varies a lot from one person to another.


This couldn't be truer. I find 6500K to be insanely yellow, so I prefer 8000K to 10000K.


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## pandragon (Jul 10, 2014)

I have a few 5,000k bulbs from the same manufacturer (phillips) in floor and desk lamps that look nearly purple, no where close to the clean white of the 7k, or was it 10k(cant remember) in my finnex light above my 29g. I don't trust color temp as a rule, more of a general guideline to help find a starting point.


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## TropTrea (Jan 10, 2014)

pandragon said:


> I have a few 5,000k bulbs from the same manufacturer (phillips) in floor and desk lamps that look nearly purple, no where close to the clean white of the 7k, or was it 10k(cant remember) in my finnex light above my 29g. I don't trust color temp as a rule, more of a general guideline to help find a starting point.


If you look at the attached chart you will see what the true color of a light source is at a specific color temperature along the arched line. This is determined by the color that black iron will appear when it is heated to that temperature. The ray lines that come out of are there to indicate in deeper color concentration what tint that color temperature produces.

One thing that also needs to be kept in mind is everyone's eye does not see light and color the same. The color is sensed in your eyes by three separate sensors one for red, one for green and one for blue. But everyone's sensors are not sensitive in exactly the same ratio. Some individuals may have a sensor that is so much weaker than the other that are considered to be blue green color blind, for others another sensor may be weak and they become red green color blind. etc. But if one of your sensors is only slightly weaker or even slightly more sensitive that the other you preconception is slightly different than someone else.

then this the factor of the actual color temperature as related to what a manufacture claims it is on a specific light bulb. They can get away with this by adding the CRI factor which indicates that is basically XX percent of what the true color temperature point is on the chart. At a CRI of 90 it could have up to 10% more or less red, or 10% more or less green or 10% more or less Blue that than the true color temp. Having a CRI above 90 is extremely rare, many CRI ratings are in the mid 80's but some of them even lower.


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## raminaniston (Dec 24, 2014)

Good idea .


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## TropTrea (Jan 10, 2014)

An added note on this.

From the Florescent bulbs I have used the highest CRI were from GE Chroma 5,000K bulbs. I had used these for years in a ration with 50/50 with various 6,000 to 6,500K bulbs with very good results. 

Right now I using more LED's lighting on my tanks. I have found that 4,500K are giving me much better results than 6,000K LED's. However a combination of the two are again giving me even better results.


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## Bluefin (Oct 29, 2014)

alot of people prefer the 6.5k bulb mixed with a 10k bulb. 10k bulb in front


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## Newt (Apr 1, 2004)

If you want more of a yellowish hue go with a 4100K.
Most if not all bulbs in the 5000K to 6500K range have a huge green spike. Especially the cheaper tubes.

In photography, red is warmer and blue is cooler. The Kelvin Rating for light bulbs is reversed with red being cooler and blue being warmer. To say a yellow hue to your tank looks warmer to you is not incorrect.


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## TropTrea (Jan 10, 2014)

keep in mind that your eye only sees three colors. red, green , and blue. So yellow to you eye is combination of red and green. To increase the yellow you see you need to increase either the red or green dependent which your eye is seeing less of.


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## Newt (Apr 1, 2004)

Or you could just buy a bulb whose combined spectral output yields a yellow color. The Sylvania GroLux Wide Spectrum (not the GroLux Std) is 3400K and is a very warm yellow/dim look and a decent CRI. The only problem is they are T12, can be hard to find at a decent cost when you factor in they only last 6 months. After that the WS and the Std. fall way off in output - by like 60% loss.


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## Grizzle Fish (May 29, 2014)

TropTrea said:


> keep in mind that your eye only sees three colors. red, green , and blue. So yellow to you eye is combination of red and green. To increase the yellow you see you need to increase either the red or green dependent which your eye is seeing less of.





Newt said:


> Or you could just buy a bulb whose combined spectral output yields a yellow color. The Sylvania GroLux Wide Spectrum (not the GroLux Std) is 3400K and is a very warm yellow/dim look and a decent CRI. The only problem is they are T12, can be hard to find at a decent cost when you factor in they only last 6 months. After that the WS and the Std. fall way off in output - by like 60% loss.


Thanks to both you folks. Yesterday I was reading a post about lighting that both of you contributed to that was very informative and I learned a lot from it.

I actually ordered a different bulb and it arrived in a thousand pieces! So I may just live with it the way it is without changing bulbs. Also, it may look different once the tank has water in it.

I'm trying to get up the courage to buy some aquarium plants for it. Recently I took a bunch of trimmings from two types of Coleus house plants and stuck them in twelve little pots. I have the pots sitting on a tray on top to my aquarium as I wanted to see how well the light fixture performed, and also if I could grow anything from just cuttings. Well, see for your self&#8230;

The lighting, which is sitting above on brackets, does the job! The plants, which started at 2", are low and broad leafed with beautiful color and as you can see are turning into a jungle. 










~Grizz


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