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Unread 11/16/2007, 04:10 PM   #52
hahnmeister
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Join Date: Sep 2005
Location: Brew City, WI
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"PAR is not cumulative. PAR is how much light is reaching the coral at this moment in the span of one second per square meter. The light is there or not there. So, why is measuring MegaMol/m2/day useful - I do not understand?"

I never thought it was either at first... but I suppose so! Its mentioned in Sprung/Delbeek's last volume (3) in the lighting chapter as well. The daily photoperiod is what is important to the corals. Most of the info Dana and I have talked about has been MegaMol/m2/day. It took some getting used to for me as well. It makes sense though... photosynthetic cells are alot like solar systems and batteries all in one. They 'charge up' and convert radiant energy to the energy the organism needs, as well as for chemical conversion processes for physical mass buildup. So corals are a bit like batteries (plants are as well), and when you look at it like this, yes, the daily photoperiod is what matters. There are limits... like putting a coral under more light than it can handle will just overload its defenses and it will bleach, and putting it under too long of a photoperiod will disrupt the corals night process... but lets say you have a coral that gets 6 hours of light at a PAR of 300, or 9 hours at 200... its the same thing in the end. The higher intensity might cause for more pigmentation to develop to protect the coral (or sometimes this happens in reverse because the light part of the photosynthesis is more than the other energy sources and an imbalance is produced), but thats about it.

If you like PM me your email and I can send you an interesting file of info I asked him for.



Last edited by hahnmeister; 11/16/2007 at 05:04 PM.
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