Blue light question.
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Vale!
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What a neat observation!
On the face of it, either the wavelength of the blue LEDs could be straying into uV (<400nm) or the blue LEDs could be running hotter than the others. Pending input from physics-savvy FMs, I'll make some enquiries about which is more likely, or if there could be another explanation. Would the diffusers on blue LEDs be different from those on white LEDs?
What brand/model is the unit? Maybe we could find out exactly which make/type the LEDs are and go from there?
On the face of it, either the wavelength of the blue LEDs could be straying into uV (<400nm) or the blue LEDs could be running hotter than the others. Pending input from physics-savvy FMs, I'll make some enquiries about which is more likely, or if there could be another explanation. Would the diffusers on blue LEDs be different from those on white LEDs?
What brand/model is the unit? Maybe we could find out exactly which make/type the LEDs are and go from there?
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plankton
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Very interesting! 
I thought algae like blue light?
I thought algae like blue light?
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codheadjohn
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I always thought it was the opposite, but not something I know much about. Blue light also has more energy, so it could be a heat thing, but seems less likely than it being a wavelength that the algae doesn't like.
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Vale!
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Funnily enough I was idly reading around this subject yesterday, in relation to Stephen's recent 'algae' thread.
The bit that I was most interested in was any relationship between light of differing wavelengths and Stephen's invader(s). Blue light is particularly relevant with respect to red algae and/or Stephen's stuff because of the type of chorophyll and carotenes that they carry, and because blue light penetrates deeper than (say) white.
Most/all algae seem to respond positively to both red and blue light wavelengths.
I think I saw (but skimmed past because it wasn't my prime focus) that some white LEDs may emit more blue light than (say) incandescents, fluorescents or metal halides etc.
The bit that I was most interested in was any relationship between light of differing wavelengths and Stephen's invader(s). Blue light is particularly relevant with respect to red algae and/or Stephen's stuff because of the type of chorophyll and carotenes that they carry, and because blue light penetrates deeper than (say) white.
Most/all algae seem to respond positively to both red and blue light wavelengths.
I think I saw (but skimmed past because it wasn't my prime focus) that some white LEDs may emit more blue light than (say) incandescents, fluorescents or metal halides etc.
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fr499y
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Yes very true. You will find 7500k contain plenty of blue light. Infact, LED's from 6500-7500k peak in blue light.
5500-6000k are a bit better, but still peak in blue
Its only when you hit the low kelvin that the reds take over. 2900-3200k
Which is why a white only LED unit works best when its a mix of 4500k warm white and 6500-7500k cool white.
5500-6000k are a bit better, but still peak in blue
Its only when you hit the low kelvin that the reds take over. 2900-3200k
Which is why a white only LED unit works best when its a mix of 4500k warm white and 6500-7500k cool white.