Quote:
Originally Posted by tripsandfalls
In terms of growth, there are photosynthetic pigments that absorb into the visible as well (and even approaching the near IR... or well into the red), but the most common ones (the chlorophylls) absorb around the wavelengths that 'blue' and 'white' LEDs emit. http://reefbuilders.com/2010/08/23/c...nfrared-light/ |
Just a slight correction. Chlorophylls a and b absorb best at about 475 and 680 nm. They utilize energy from 680 nm photons more efficiently than at 475 nm as the former have an energy content closely matching the ideal level of chlorophyll excitation. In terms of growth, we are primarily concerned with chlorophylls a and b. The more colourful pigments (carotenoids) serve more of a photoprotective role and do not have a major impact on growth, at least in algae.
White LEDs as I'm sure you know are a mix of wavelengths. So you can't say a pigment absorbs best at the wavelengths white LEDs emit, since they emit a very broad spectrum.