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Re: Fluorescent light fixtures



> > 3) The sleazo fixtures seem to greatly shorten the life of some bulbs,
> >    most notably Tritons.  Consumer Reports noted this same thing when
> >    they tested compact FL bulbs that are designed to replace incand.
> >    bulbs - some electronic ballasts greatly shortened the bulb life.
> 
> 	Gotta agree, again.  My tritons burned out after less than a year
> 	(yeah I know I'm supposed to replace after 6 months) and the Vita
> 	Lites didn't last much longer.  The LOA ballasts start the bulbs
> 	instantly, blasting them with an electric charge that's accompanied
> 	by groaning from the entire fixture.

All I know is what I read (generally :->); hopefully someone will be able 
to enlighten me if my information is way off base.

The Pet Warehouse catalog has in bold type in the text for triton bulbs, 
"Requires starter."

The Time-Life book How Things Work in Your Home (and What to Do When They 
Don't), which  contains the best description on fluorescent lights I have 
found in my local library, has the following discussion on fl. lighting.  
There are three types of starting technology.  (1) preheat - an 
auxiliary starter is used to heat the tube ends and strike an arc across 
the tube.  (2) rapid start - a special ballast applies a relatively low 
voltage directly to special, quick-heating cathodes (tube ends).  (3) 
instant start - the ballast supplies a voltage spike of magnitude up to 4 
times the normal operating voltage of the bulb.

Most aquarium hoods are of the preheat type, which Pet Warehouse says its 
bulbs require.  Shop lights and most 40W systems are of the rapid start 
type, which Time-Life says requires special cathodes in the bulbs.  It 
seems likely to me that although a rapid-start ballast may light a 
preheat bulb, excessive wear will be caused at the cathodes, reducing the 
lamps brightness and useful life.  Since old bulbs are usually indicated 
by dark spots at the bulb ends corresponding to deterioration of the 
cathodes, this explanation seems plausible.

I can't find anyone locally who can answer the question of whether there 
is really any difference in bulbs designed for preheat and rapid start 
systems.  Since this is something of a burning issue for me, I welcome 
enlightenment from someone who does know.  Since many of the fixtures 
say "Rapid start bulbs only," I assume that there is, at least 
theoretically, a difference.