Lighting intensities

> From: Erik Olson <olson at phys_washington.edu>
> Date: Sat, 13 May 1995 08:46:02 -0700 (PDT)
> Subject: Re: Aquatic Plants Digest V1 #67
> > From: Mark Wickersham <mwickers at minerva_cis.yale.edu>
> > Date: Fri, 12 May 1995 22:44:01 -0400 (EDT)
> > Subject: More on E.tenellus; [blank]-Glo bulbs?
> > 
> > 2) The shopkeeper with whom I discussed the above discrepancy in 
> > references claimed that I could vastly improve my lighting performance by 
> > purchasing a Life-Glo bulb: 20W, 24", but it has 240 Lux!  Biolume, in 
> > comparison, apparently only gives 80 lux.  Am I missing something? 
> FYI, Usually we barter in Lumens, not Lux.  But this sounds inherently wrong.

Hmm.  I just reread Booth's article, to which you referred me in response 
to my first question, and it gives Lux values for all of his bulb tests, 
not lumens.  According to Barry James's book, "The amount of light 
reaching a surface is measured in lux, which is equivalent to lumens per 
square meter."  The principal reason I used lux in this question was 
because that was the only striking difference in the manufacturer's specs 
between its several bulbs.  All the lumens were approximately the same.  
So what I was specifically wondering was whether focusing the output, as 
this light seems to do, is helpful.  Booth's analysis in his several 
interesting articles seems to show that internal reflectors are not worth 
the extra expense.  He compared the Biolume (that's what I've been using; 
it has a built-in reflector) with the Trilux, and discovered that it 
does not perform favorably.  At the shop selling these Life-Glo bulbs, 
though, there was no question that the light was *much* brighter coming 
from the Life-Glo than from a new Triton (also a bulb I have used' it, 
too, has an internal reflector).  Booth's article also compared the 
Power-Glo with several other bulbs, measuring primarily their color 
temperature.  Unfortunately, his articles do not address the Life-Glo 
bulb, which, again, is the only [blank]-Glo bulb that has this intense 

It is obvious to me that there is no way of getting around the need for 
multiple bulbs, and eventually that is what I will do, but until then I 
was hoping for better plant growth with minimal outlay.  (I am stuck with 
my single-bulb strip light that fits my Perfecto hood which I purchased 
well before I discovered that plants were not as difficult as unearthing 
the holy grail.)  I will probably invest in an Ultra Trilux next, judging 
from the results of Booth's tests.

Take care.