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Fluorescent Lighting


  1. Fluorescent Bulbs and some comments ....
    by (Heide BT) (Sun, 19 Apr 1992)
  2. GFI no help through ballast
    by scottn-at-fluffrag.Eng.Sun.COM (Scott Nye) (30 Jun 1992 21:26:13 GMT)
  3. GFI no help through ballast
    by (Anthony Tse) (1 Jul 92)
  4. Light rec. for 55gal
    by (Paul A Prior) (16 Feb 1993)
  5. Light rec. for 55gal
    by Erik Olson (Tue, 16 Feb 1993)
  6. Rapid start conversion - ?
    by Larry Bunge <> (Wed, 26 Jul 1995)
  7. re:Instant Start
    by "shaji (s.) bhaskar" <> (02 Dec 1996)
  8. Shocking Lights
    by wayne jones <waj/> (Wednesday, April 08, 1998)

Fluorescent Bulbs and some comments ....

by (Heide BT)
Date: Sun, 19 Apr 1992
Newsgroup: rec.aquaria

In article <> writes:
>1. Will a 24" T-12 bulb put out more light compared to a 24" T-8? How does  
>the output compare to a 36" T-8?

I'm no expert, but a T-12 would have more surface area than a T-8, which
would imply more phosphore. However, does the phosphore of a T-8 glow more
intensly than a T-12? I have both T-8 and T-12 24" bulbs for my 23 gallon
tank. The T-8's seem to be just as bright as the T-12's, but this is only
by eye. Of course the brightness also depends on the make of the bulb and
the phosphores used in it. My T-8 is an Aqua-Glow, and the T-12 a Grow-Lux.

>2. Is seems like the T-12 and T-8 bulbs use the same size standard end clips,  

In my experience, yes.

>3. It also seems like the T-12 bulbs should use special ballasts, different  
>from the T-8s. If I use a standard shoplight which is designed for T-8 bulbs,  
>can I expect that I could also use T-12 bulbs with it?

As far as I know, you can use the same ballasts, I do. I also have an 18"
T-8 on my 10 gallon tank. It uses a ballast designed for 20, 15 and 14 Watt
bulbs of the 24" and 18" variety.

>4. If I have a choice, should I get the thicker T-12 bulb instead of the same  
>length T-8? Is there much of a price difference?

It's hard to say. I haven't seen the same brand, with the same specs and same
length available in both T-8 and T-12.

Now I would like to make an interesting observation about ballasts and
starters that I have not seen anyone else mention on the net (though I
haven't been here long). When I bought my first tank it was a Hagen with
a flourecent canopy. From the beginning I intended to run it on a timer.
Imagine my anoyance when I discovered it used  a manual switch starter
so that it wouldn't turn on when the light timer went on - it required a
human finger each time. It was a 24" single fixture and cost me
$50 Cdn without the bulb. I felt quite ripped off, especially since a 
ballast with an automatic starter cost me only $20 at the local hardware

So after purchasing and installing the ballast with the auto starter, I
thought my troubles were over, but they were not. The light would not always
come on right aways, sometimes taking a few hours. I thought this might
be because the Hagen reflector was made of platic, so I added grounded
aluminum foil behind the bulb, but this didn't help. Now I discovered that
it was only the wide spectrum type bulbs (Grow-Lux, AquaGlow etc.) that
were giving me this problem. I regular GE cool white would start each time.

I had the same problem when I built my 18" light for my 10 gallon. I finally
solved the problem by using those small cylindrical capacitance starters
in combination with the ballasts (they make a clicking noise when they
start the bulb). Has anyone else had this problem or experience? Also, I
can buy the starters, but I can't seem to find anybody who sells the 
mounting sockets they are designed to plug into.


GFI no help through ballast

by scottn-at-fluffrag.Eng.Sun.COM (Scott Nye)
30 Jun 1992 21:26:13 GMT

In article <> (Jim Hurley) writes:
>I asked on 'sci.electronics', but the best answer was that it was a black
>art and that I should request manufacturer info from Silvania, GE, and/or

This is a good idea. All of these comanies have 1-800 numbers and
have lots of good info for free. Phillips has a $18 lighting handbook
that has tons of useful info in it, as well as lots of free
literature. For information on ballasting lamps, I would try some
of the electronic ballast manufacturers. These include EBT, Magnetek,
Advance, Motorola, Valmont. The new push for the use of electronic
ballasts has caused many of these manufacturers to publish lots
of good info on the operational characteristics of lamps.

>Since I'm installing 24 flourescents this week on my new aquarium racks, 
>I was thinking a bit about them.

Definitely use electronic ballasts. Motorola Lighting has a good
matrix showing power savings for many permutations or tar/electronic
ballasts. Besides, electronic ballasts aren't really that much more
expensive. I just picked up 2 EBT's for 27.00ea. I chose EBT because
they are the oldest manufacturer, although I think I might have bought
motorola had they been easier to find.

>Can anyone post or send me e-mail about anything they know, or mention
>references I can read to brush up on the topic.

see above ...

>What I know is that most flourecents have a heater filament at each
>end, and mercury vapor inside the tube. The heaters warm up
>the mercury vapor so that it is more readily conductive. The thing
>that starts the lamp is a high voltage kick across the two filaments.
>This causes the mercury to conduct and form a plasma that emits UV.
>The ballast and/or starter provide the kick while the inductance
>limits the current flow through the tube. While conducting,
>the UV radiation hits the tube phosphors, is absorbed, and
>re-radiated at other wavelengths.
>I'm not very clear on how the various types of power supplies provide
>that initial kick and what happens to the heater current while the
>lamp is on.

A couple of other useful points. The time during which the plasma stays
a plasma in the absence of current flow through it is very important.
At 60hz., the plasma will deionize every cycle. Thus each succeeding
cycle must reionize the plasma, which is what causes flicker. High
frequency electronic ballasts re-energize the plasma before it deionizes,
greatly reducing flicker. The persistence of the phosphor in the tube
is also important here. Because many of the phosphors in  flourecent
lamps are short persistence, they are less efficient when excited
by lower frequencies.

As far as the cathode bias (heater current) goes, rapid start lamps
maintain the cathode bias. Modified rapid start lamps reduce the
cathode bias to save power, this also reduces lamp life. Phillips
derates their lamps about 25% when operated in either pre-heat
or modified rapid start configurations.

Scott Nye

GFI no help through ballast

by (Anthony Tse)
1 Jul 92 20:58:27 GMT

In article < (Greg Smith) writes:
=I have done that at all lighting stores in my phone book. (Cleveland Ohio)
=>I am sure they have them in stock.
=They said they didn't.  Maybe they didn't know what I was talking about
=I was looking for 40 watt electronic ballasts.

	Call the 800 directory and get the number for Advance and Magnetek
(sp?).  Call them up and see do they know any dealer around your
area and get a model number while you are at it.  


Light rec. for 55gal

by (Paul A Prior)
Tue, 16 Feb 1993 16:21:35 GMT

In article <> (John Hawthorne) writes:
>A word of warning!  There was a thread on here a few weeks ago questioning
>the reliability of the cheap "electronic" ballasts.  I was skeptical at
>first but am now a believer.  These cheap shop lites may be okay for
>generic bulbs, but I've lost 2 48" Vitalites after less that 2 months use.
>Could be coincidence, but with the price of hi tech bulbs I'm taking no
>more chances and have a different electronic ballast on order.

Another data point: I've been using two LOA $8.99 ballasts for a couple of
years now and they continue to work flawlessly.  The only complaint I 
have is that they are too long for the hood I built and I had to tear
one of them apart and the other sits partially exposed.  Not sure whether
any other brands are any shorter.

-- 621-8240----------------
Paul A. Prior    Ban anchors, not reef tanks  "Not that there is anything   
3rd year medical student 		        wrong with that..." SF
The Ohio State U. College of Medicine   Tobacco Kills- Please don't smoke!

Light rec. for 55gal

by Erik Olson ((e-mail))
Tue, 16 Feb 1993 16:40:45 GMT

In article <> (Paul A Prior) writes:

>Another data point: I've been using two LOA $8.99 ballasts for a couple of
>years now and they continue to work flawlessly.  The only complaint I 
>have is that they are too long for the hood I built and I had to tear
>one of them apart and the other sits partially exposed.  Not sure whether
>any other brands are any shorter.

And another... I've used three LOA shop fixtures.  The first had a contact 
break on the ballast right after I put it in.  The one I replaced it with 
has worked fine for 2 years, as has a second unit.  They've had 
SpectraLites (Vitalite knockoff by Sylvania(?)) and Grolights.

Rapid start conversion - ?

by Larry Bunge <>
Date: Wed, 26 Jul 1995
Newsgroup: rec.aquaria

Some general notes about flourescent lights.

- the flourescent tubes themselves are ignorant of what starts and powers them.

- the starting and powering of these tubes may be done in one of three ways:

   (1) a standard ballast with a push-button starter circuit. (Useless with a
   (2) a standard ballast with a separate flourescent tube starter. (You can
       convert the above to this by adding a starter).
   (3) a rapid start ballast with the starter circuitry built in.

- The last is the best and really is not expensive. It is becoming the standard
  in place of having a separate starter. I pay $11 for a quality rapid start
  ballast for 2 40-watt bulbs. Finding a socket for a starter and all the other
  hassle is not worth it unless you happen to have it on hand.

- Ballasts are designed to power a specific tube arrangement. You must obtain
  the right ballast for the tube-size and number of tubes in the circuit,
  otherwise you may damage the tubes.

- Instead of running down to your "Home Depot" type store go to an electrical
  supplier. These are generally wholesalers to electrical contractors. I find
  they are cheaper, carry more items and they definitely know a lot more.

- Water resistent end caps are an aquarium specialty and you doubtfully will
  find them anywhere execept through an aquarium supplier.

- All of the above applies to standard flourescent tubes as commonly supplied
  with purchased hoods and to specialty bulbs such as "DayLight" and
  "AgroGrow" as are available at electrical suppliers.

- If you are purchasing some of those very expensive tubes aimed at the reef
  market then there could be some special ballast/starter recommendations from
  the manufacturer that you should follow, such as using "electronic" ballasts
  to preserve tube life.

re:Instant Start

by "shaji (s.) bhaskar" <>
Date: 02 Dec 1996

> From: Erik Olson <(e-mail)>
> > From: "shaji (s.) bhaskar" <>
> >
> > To set the context - both bulbs *and* ballasts are classified as
> > either instant-start or rapid-start. Most combinations of ballasts
> > and bulbs will work:
> >
> >                          Instant-start bulb    Rapid-start bulb
> >                        -----------------------------------------
> > Instant-start ballast  |        OK            |      OK        |
> >                        -----------------------------------------
> > Rapid-start ballast    |     WON'T WORK       |      OK        |
> >                        -----------------------------------------
> >
> > Rapid-start bulbs have two pins at each end, while instant-start bulbs
> > have only one pin at each end.  What Erik is using is apparently an
> > instant-start ballast with rapid-start bulbs.
> Are you sure 'bout that?  I wonder if the two pins in the T-8 48" bulbs
> are there just because a 1-pin 48" mounting doesn't really exist.  (Note
> this is pure speculation; I have no facts to back this up, at least until
> I go talk to my local lighting people).  Are folks using rapid-start
> ballasts with T-8's?

I'm positive that instant-start (I-S) ballasts can start rapid-start
(R-S) bulbs.  I am also positive that T-8 R-S bulbs and ballasts
exist.  As to whether your particular bulb is I-S, I can't really
say. It is possible that you have an I-S bulb with two pins just so
that retrofits of existing fixtures are easy (retrofits are a big
market segment for commercial lighting).  My best guess is still that
your bulbs are R-S.

Here is a related quote from
by Steven Mesh (a man with impeccable credentials, he's apparently an
academic :-)) on the differences between R-S and I-S.  BTW, is a good site for lighting info - just
use the search engine. 

*********** Begin Quote **************

Rapid-start fluorescent lamps contain electrodes (filaments) at either
end of the lamp. They can be identified by bi-pin bases. These
electrodes are preheated for at least one-half second. Once the
electrodes are brought to the appropriate temperature, the arc is
struck and the lamp produces light. Instant-start lamps have
single-pin bases, so there is no opportunity for preheating the
electrodes. Instead, the ballast applies roughly three times more
voltage to the lamp than a rapid-start system.

This jolt of electricity can be detrimental to the life of the lamp's
components, especially the electrodes. Therefore, instant-start lamps
typically have a rated life of 15,000 hours versus 20,000 hours for
rapid-start. These figures are based on three hours of operation per
start. In the past, many lighting systems were designed on the basis
of 12 or more hours of operation per start. At that rate, both lamp
types approach the same life -- 29,000 hours.

Incidentally, rapid-start lamps can be operated by instant-start
ballasts. In this case, the life of the rapid-start lamp is derated to
15,000 hours at three hours per start. Instant-start lamps cannot be
powered by rapid-start ballasts since there is only one pin at each
end of the lamp. (Preheating of the electrode requires a complete loop
of electricity, hence the filament and bi-pin base.)

Typically, rapid-start lamps maintain the electrode heat during normal
operation. This consumes an additional three watts of power not
converted into light.  Instant-start lamps do not require electrode
heating. Therefore, an instant-start lamp and ballast combination can
slightly reduce energy use. This is a similar technique to using a
hybrid (heater cutout) ballast.

Depending on the operation of a particular facility, it may be
possible to save money by using instant-start technology. On the other
hand, many states now require owners to equip their facilities with
motion detectors, infrared sensors, local wall box switches and even
photocells for daylight sensing. In these cases, the energy and cost
savings may be diminished because the reduction in lamp life will
increase costs for relamping and labor.

********** End quote *************


Shocking Lights

by wayne jones <waj/>
Date: Wednesday, April 08, 1998
To: Erik Olson <.nospam>

A trick often used by electricians when mounting flourescent tubes where a
remote ballast is used due to lack of space is to mount the tube holders to
a length of 1 1/2" stiffening channel . The clips will fit nicely over the
ends of the channel and the channel provides a place to ground your
In fact, in ontario this method is accepted by the local electrical
inspector. The channel is available at any place that sells drywall and
steel studs, the channel is used to stiffen steel stud walls. It comes in
12' lengths and one length can be cut with a hacksaw into three 4' lengths.
I am not sure of the price but I think it's about $3 canadian.

wayne jones

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