Lighting, part deux

>From: Stephen.Pushak at hcsd_hac.com

>The submissions on lighting have been really good and helped me
>understand the issues a lot better.  I was wondering if anybody had
>seen a study of aquatic plants grown under identical conditions with
>different lighting?  Can we tell how much better plants would grow if
>they had a wide spectrum?

Plants and spectrum has been a long and varied topic of research from
grade school science fairs to career long studies.  You can search the
literature for the gory details.  You can spend a life time at it.

>  Keith is saying this whole issue is not as
>important as we suspected and I would like to believe that is true.

Humm, that's not quite what I said.  I said it was easy to get too
up-tight about it, not that it isn't important!  Of course light is
very important for any photosynthetic organisms, aquarium plants
included.  But, we're now to the point that there is enough of a
selection of good spectrum bulbs that you just place a sufficient
number of a daylight combo you like and you'll get good results.  You
get 90% of the results for 10% of the effort.  There will always be
those who're looking for that extra 10% and will spare no time or
money getting it; efficiency, spectral output, lumen charts, all will
be examined to the nth degree; flame wars will be waged.  But it isn't
worth it.  Just look at the Krib photos and you'll see gorgeous tank
after gorgeous tank, all using different lighting solutions.

BTW, it still doesn't seem to be common knowledge yet that lumens are
pretty much irrelevant as a determinant for plant growth suitability.
Lumens are a measure of output as weighted by some average human
retnal response curve.  This is an understandibly important parameter
if you're making bulbs for human visual use.  It doesn't have diddly
squat to do with the response curves of photochemically reactive
molecules in plants.  So don't put too much stock in the efficiency
numbers you see (lumens/watt).  It has a lot to do with how well you
can see your plants but not a whole lot to do with what your plants
see.  Ditto for CRI.

Pruning weekly while currently using a 40W SPX and VitaLite combo,

Keith Rogers
krogers at es_com