lighting question ( again)

If you are trying to go for a plant light, the 6700K is better than either of those IMO. Both are at the top end of the spectrum for plants so between them I would favor the 10000K. If you want to light a reef tank then you might use the 12000K instead. Natural sunlight, the stuff our plants are fully adapted to use after many millions of years of evolution, runs between 5500K and 6500K depending on what source you believe. The higher temperature, shorter wavelength of your selected bulbs is far from ideal for a plant adapted to real sunlight.
 
Kelvin rating isn't so important to plants within a certain range. I find a mix of 6700 and 10000K is pleasing to the eye. With one bulb it's hard to say as it depends on the person. Although compared to 12000, 10000 would look better IMO.
 
Im looking for a good low cost set of lights for my tank 48 inches long ( for the 55) and at least 200 watts 2 cords ( so I can turn off one set at a time. ) t-5
 
Will these 48" lights be going over your new 55? Will you be dosing ferts and running co2? If not, you might not want 200w. 100-150 watts might be better if you're going low-tech, or no-tech, really.
 
A related question - can you get CFLs at 10000K?
 
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