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?
> 1) I read in B. James that lighting for e.tenellus is "Not critical" (one 
> of the least descriptive terms he uses), but in several other references 
> in a local shop I read that, as a "lawn" plant, it requires "strong 
> illumination."  My 24", 20W Biolume does well for Java Fern and, I hope, 
> c.wendtii and a.nana, but will that be enough for e.tenellus?

I don't think they'll be happy with one tube, Biolume or not.  For it to 
propagate well, it should have 2-4 tubes above a modestly-deep tank (18").

Biolumes, btw, aren't worth the price.  See George Booth's article on the 
web as to why reflectorized bulbs are more hype than anything else:

> 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.

> He 
> maintains that in his 30g tank (same as mine, 36x15x12), his high-light 
> plants grow like crazy with this bulb.  The same manufacturer offers 
> Sun-Glo, Power-Glo, Marine-Glo, and Aqua-Glo.  The Life-Glo, though, has 
> by far the highest lux.  It has a painted(?)-in reflector that only 
> allows light to exit out the side pointed, obviously, towards the tank.  

Again, read George's article.  The reflectorizing does little to enhance 
the intensity, and actually PREVENTS enhancement by external reflectors.
It's a gimmick!

  - Erik

Erik D. Olson                		
olson at phys_washington.edu