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[APD] RE: 10K

>The working assumption being that Hovanec is right when he says:

>"Plants have two types of chlorophyll, a and b. Chlorophyll a absorbs
light at 405 and 640 nm. Chlorophyll b has a peak absorption at 440 >and
620 nm."

He's right............but that's not all of the story........ plants can
and do vary their Chl a and b ratios and have many pignments they can use
to collect and maximize.........or minimize the incoming light.
They (the Chl a and b light harvesting complex) have many other peak
absorbancies besides the chl a and b that are isolated. These LHC's are
quite efficient at this energy transfer. Not much loss eitherway. 
A plant needs to be able to adapt and they do. 
The light harvesting comoplexs are not merely limited to the peak
absorbancies of the Chl a and b.

How you apply this knowledge is (more)important as what the peak absortion
of a single part of the LHC is or is not.
It's one part and the LHC filters this energy down to either P680 of P700nm.
All energy transfers go to these special wavelengths.

So in the end as far as the plants are concerned, it doesn't matter too
much. This has been show in the research when cool white vs all these fancy
pantsy aqaurium and plant grow bulbs were tested against one another with
relative growth rates.
Plants can adapt fairly well to most lighting, it gets back to efficiency,
style and the color our eyes enjoy.
Rather than blue is better or can penetrate deeper etc, red is the more
important color, but a little blue helps balance the color.  

So rather than getting a wild hair and running off on some chase that some
light is better than another light or suggesting it's going to grow plants
better and produce less alage, let me sell you some snake oil:-)
"Tom's secret swamp snake sauce, none better."  
Your own opinion of the way the color appears to your eyes plays the
largest role. 

I like some blue with mostly red and perhaops I have a more red eye than
most of you blue bloods which seems to be the trend these days, all this

But atinics are not particularly useful IME/IMO. Make colors look
cool/weird/ugleee depending on your views.
I don't use them on the salt tanks either.

Tom Barr

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