Halogen kelvin temp
- Thread starter JimmytheCrud
- Start date
Kelvin & wattage are unrelated. I wouldn't use halogen because they are too hot, inefficient, and they don't render colors very well. Flourescents are much better. Furthermore, you don't need that kind of wattage on an aquarium. There are far better choices, like higher intensity flourescents such as VHO, power compact, and T-5's.
For growing plants, anything above 4000K should suffice.
For growing plants, anything above 4000K should suffice.
The short answer: No
The long answer:
Kelvin temperature by itself doesn't really tell you much about useful spectrum. Plants primarilly utilize light around wavelengths of 650 nanometers (orange-red) and 450 nanometers (blueish-violet). The lower the temperature, the more lacking in the blue end of the spectrum, so you are on the right track. That is one of the reasons reefers use actinic bulbs--to supplement the high frequency (short wavelength) blue light.
A bulb in the 2700K range (sounds almost like a High Pressure Sodium light) would probably have a yellowish-green color. Plants appear green because they cannot utilize light in the green and yellow portions of the spectrum, and therefore reflect it. If most of the light is in this range, it is doing almost nothing for the plants. It would be making the electric company lots of money and heating your house, though.
According to this thorough description about tungsten halogen lamps, they have a luminous efficacy of about 30 lm/W (or less if artificial means are used to raise the color temperature above 3200K). The 5000K fluorescent tubes I am currently using have a rated luminous efficacy of 92.5 lm/W (3700 lumens/40 watts). So, in simple terms, it would require between 493.3 (luminous efficacy of 30 lm/W) to 672.7 watts (luminous efficacy of 22 lm/W) to produce the same quantity of light as I do with only 160 watts. As an added benefit, my tubes also have peaks at 450 and 620 nanometers... real close to where they need to be.
The long answer:
Kelvin temperature by itself doesn't really tell you much about useful spectrum. Plants primarilly utilize light around wavelengths of 650 nanometers (orange-red) and 450 nanometers (blueish-violet). The lower the temperature, the more lacking in the blue end of the spectrum, so you are on the right track. That is one of the reasons reefers use actinic bulbs--to supplement the high frequency (short wavelength) blue light.
A bulb in the 2700K range (sounds almost like a High Pressure Sodium light) would probably have a yellowish-green color. Plants appear green because they cannot utilize light in the green and yellow portions of the spectrum, and therefore reflect it. If most of the light is in this range, it is doing almost nothing for the plants. It would be making the electric company lots of money and heating your house, though.
According to this thorough description about tungsten halogen lamps, they have a luminous efficacy of about 30 lm/W (or less if artificial means are used to raise the color temperature above 3200K). The 5000K fluorescent tubes I am currently using have a rated luminous efficacy of 92.5 lm/W (3700 lumens/40 watts). So, in simple terms, it would require between 493.3 (luminous efficacy of 30 lm/W) to 672.7 watts (luminous efficacy of 22 lm/W) to produce the same quantity of light as I do with only 160 watts. As an added benefit, my tubes also have peaks at 450 and 620 nanometers... real close to where they need to be.
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