Re: In defense of Watts-per-gallon -- or - Plugging an old adage

["Philippe Lemaire" <ph.lemaire at CompaqNet_be>]

I also think this rule is a good starting point to be tempered by
the tank height.

Going to candela/lumen will NOT improve anything IMHO for
only ONE wavelength nice to human vision is taken into account
in these International Units.

Moreover I have the impression that more you give green light
to plants more they lose their red/brown hue to be simply green.
So I will favorise red/blue tubes vs. others...

My lonely opinion.

Philippe


Date: Tue, 11 Feb 2003 04:25:00 -0800 (PST)
From: "S. Hieber" <shieber at yahoo_com>
Subject: Re: In defense of Watts-per-gallon -- or - Plugging an old adage

Jeffery Ludwig expressed dissatisfaction with the use of
watts per gallon as a measure of the amount of light.

The best would be to measure the actual output of actual
lamps (reflectors and bulbs) in place in a given
circumstance and compare that to the specific spectral
needs of the plants in that tank.

Short of that, one could use the spectral output ratings
for a lamp using particular bulbs.  But you won't find this
for many (any?) lamps (reflector and bulb) -- you'd even be
hard pressed to find this info for a given bulb.  You could
substitute the lumen or candlepower rating but you will be
hard pressed to find that for many bulbs.

[other interesting remarks]

I'd rather worry about CO2 and O2 levels -- no there's
something one can get really accurate about  ;-)  

Regards,
Scott H.