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Re: Lighting

Saman wrote:

never heard this one before, but you have certainly
peaked my curiosity!  Please do elaborate!  What
exactly does this mean (for the techies out there, is
this similar to overclocking a processor? {I've had
great success with that :-)
I am assuming that you deliver more "juice" to the
bulb than its "rated" for [using a different ballast].
 I would also assume that this shortens the life of
the bulb (but for standard 4' bulbs, that would be
well worth it since they are cheaper and need to be
replaced regularly regardless).  How much more light
can you squeeze out of them? which lights do you get
the most improvement on?

Do people on the list do this? (in the U.S.? or
elsewhere?)  Please share your experiences and methods
for the inquiring minds out there.  Feel free to point
to a web-site :-]

I reply:

Well I don't know a whole lot about this myself. I know a few people do
it. When I first heard about it I was extremely skeptical but I gave it
a try and it worked. I think basically all fluorescent lamps are pretty
much the same with the main difference being that some lamps are driven
much harder than others. Lamps are classed according to this concept as
NO, HO and VHO. The gas fill and the diameter and length of the lamp
have an influence of the design current of the lamp. You can overdrive
any lamp above it's design current and it will work but there is going
to be a loss in efficiency and lamp life. Basically this is how a PCs or
a VHO lamps work. They have extra robust elecrtrodes that  are built to
withstand the extra current and phosphors that will withstand the extra

The big questions are how much overdriving is OK and what will the
effect be on efficiency and lamp life and which lamps will survive this
abuse the best. I think the best bet is to use HF lamps such as 32 watt
T8 4' lamps. They are designed for instant start anyway and they use
practically the same phosphors as most PCs. I experimented with those
lamps and wiring two outputs together to drive one lamp increased the
light output by about 50%. I checked the input current on the ballast
and the efficiency of the lamp dropped a little but not nearly as much
as expected. It's a total mystery to me what an electronic ballast
actually does but it does seem to work. Some people claim the lamps are
still good for a year. I don't have a lot of trouble believing this as I
have some lamps that have been overdriven by 20% on instant start
ballasts that are still working fine after at least 4 years. 50% doesn't
seem a whole lot more especially on the low number of starts in an
aquarium hood. There are other ways to overdrive lamps as well but to a
much lesser degree. You can just buy ballast specifically designed to do
this for light increases of up to 32% or you can use shorter lamps than
were intended for your ballast or if it is a parallel ballast you can
just remove a couple of lamps and the others will get brighter. Wiring
two outputs together seems to be the easiest and most benificial way.
Electronic ballasts that will drive 4 32 watt lamps are very easy to
come by and are also quite cheap.

I am currently setting up a 55 gallon tank with just two lamps run by
one of those ballasts. It really solves the problem of getting a lot of
light in a small space for a little money. Total cost of the fixture
including the remote mounting junction box, ballast, wiring, white
aluminum flashing (to line the hood), sockets and lamps is $60 American.
If you left out some of the not totally necessary extras like the remote
mounting, it could be considerably less.

For all I know this might be a very bad idea. The lighting gods might
become offended and cause the thing to explode but I doubt it. I don't
think it is much different than what is done with electronic HO sign
ballasts or VHO ballasts or even the workhorse ballasts that come with
an AH Supply kit. No problems so far and as far as I know no one else
has had problems either. I don't think this is a project for someone who
is looking for a completely sure thing. It may turn out to be not as
promising as it appears.