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Re: [APD] Re: Self-ballasted PC lights?



Good points all. Less lumens per watt from a lamp using a
coiled bulb. Plus the heat is concentrated in a smaller
area so myou might have hood heating issues if your hood is
plastic -- I've seen melts from using the coiled bulbs.

Scott H.
--- Bill Wichers <billw at waveform_net> wrote:
> 
> >I was wondering if anyone had ever thought about using
> or tried using self-
> >ballasted PC fluorescent lights (they have the ballast
> built into them so you
> >can use a regular lamp socket). I was considering using
> a couple 85watt 6500K
> >self-ballasted PC bulbs over my 65 gallon tank (that I
> will soon be 
> >setting up
> >as a planted tank). They only cost between $25-$30 and
> save you the cost of
> >buying (and replacing)expensive ballasts. I can see two
> possible problems 
> >with
> >this setup...
> 
> This question comes up periodically on the list so there
> are a bunch of 
> threads in the archives about it.
> BTW, a typical ballast for regular linear PCF lights will
> last more than 5 
> years IMHO. I wouldn't worry too much about factoring in
> replacement cost 
> of the ballasts in your pricing calculations since you
> will be able to 
> amortize the cost of the ballast over many years, and
> they aren't very 
> expensive to begin with unless you're getting them from
> an LFS.
> 
> >1) They are twisted bulbs instead of straight so they do
> not cover as much
> >area (they act more like a spot light)
> 
> They are closer to point source lights, but suffer from
> high restrike due 
> to the coiled tube. In a normal linear florescent light,
> light radiates 
> outward roughly equally in all directions around the
> cylinder of the tube 
> (must... resist... using vector terminology....:-). In a
> tightly coiled 
> tube, a lot of the light is emitted on the "inside" of
> the coil which does 
> little besides heating up other parts of the coil. This
> reduced "effective 
> efficiency" will translate to less of the light output
> getting into your 
> tank, so a  55 watt incandescent-replacement type fixture
> will *not* 
> produce the same *effective* light over your tank as a 55
> watt "normal" 
> (linear) PCF lamp would.
> 
> >2) You can't buy regular lamp sockets that are water
> tight like the aquarium
> >fluorescent endcaps.
> 
> This isn't really much cause for concern. I really think
> the watertight 
> endcaps are mostly marketing hype and have little
> technical value. Most of 
> them aren't even truly watertight (or stop being
> watertight after a few 
> months or years of exposure to the high-temp and
> high-humidity environment 
> above a tank). I use "regular" bases over all my tanks
> since they are much 
> cheaper and are easier to replace when they fail from
> corrosion and the 
> like. And if your hot bulb goes in the tank there is a
> good chance it will 
> break from the temperature shock and then you'll have
> electrical contact 
> with the water despite having the watertight endcaps. My
> advice: use a lens 
> of some sort between the water and your bulbs and don't
> worry about the 
> endcaps, but use a GFCI on the electrical circuit feeding
> your tank 
> equipment and *test it monthly*. Also, the breaker-type
> (as in 
> mount-in-the-electrical-panel type of breaker) GFCI's
> tend to be far more 
> reliable and longer-lived, IMHO, and I've seen a *lot* of
> both types of them.
> 
> >However, the way I look at it, people use MH lamps and
> (although much
> >brighter) they act like spot lights too. Using a good
> reflector might help
> >with this problem too.
> MH doesn't suffer from the restrike problem since it is a
> "true" point 
> source light (all the light comes from essentially one
> very small spot and 
> radiates roughly equally in all directions). As a result
> of this, it is not 
> difficult to design a good reflector to direct most of
> the light into the 
> tank. With a coiled PCF lamp, it is impossible to
> realistically design a 
> reflector capable of using the light emitted on the
> "inside" of the coil, 
> which results in that light being wasted in restrike,
> which does little 
> beyond heating up the florescent tube.
> 
> >As far as I am concerned, using a regular lamp socket
> MIGHT accumulate a 
> >bit of rust on it, but they only cost a few dollars...
> if they accumulate 
> >rust I can just replace them when I replace the bulbs
> and still save 
> >money. Coralife has the same thing in a 10watt version
> in either
> 
> Use a commercial ceramic light socket (even Home Depot
> has them) with brass 
> contacts if you can find them (many use aluminum for the
> screw contact and 
> brass for only the pin in the base). You can clean
> corrosion off of a brass 
> socket with a scouring pad or a dremel with a wire brush
> disc. You'll get 
> *years* out of even a cheap socket though unless you have
> water making 
> direct contact with it over a prolonged period of time
> (such as in the case 
> of a light socket placed over an area of the tank with an
> air stone, which 
> will create a "mist" in the air above the water surface
> in that area).
> 
> >6500k or 50/50(10,000k/actinic) so obviously people have
> thought of doing 
> >this
> >for small tanks. I am interested to hear what other
> people think about this
> >idea.
> >__________________
> 
> The basic consensus is usually that it can be done, and
> that the cheap 
> lights will work, but they're not as good as a "real"
> linear PCF is in 
> terms of efficiency or light delivery to the tank water.
> If you're on a 
> tight budget, the incandescent-replacement type fixtures
> are definitely 
> worth a try, but if you're looking for the best
> performance or electrical 
> and lighting efficiency from your system there are much
> better options on 
> the market.
> 
> Since it sounds like you are planning to DIY your
> lighting, have a look at 
> the linear PCF supplies available at
> http://www.ahsupply.com. Many on the 
> list (including myself) have had very good luck with
> their equipment, and 
> the prices are much better than the prebuilt assemblies
> the tank 
> manufactures sell.
> 
>          -Bill
> 
> 
> *****************************
> Waveform Technology
> UNIX Systems Administrator
> 
> _______________________________________________
> Aquatic-Plants mailing list
> Aquatic-Plants at actwin_com
> http://www.actwin.com/mailman/listinfo.cgi/aquatic-plants


=====
S. Hieber

-  -   -   -   -   -   -   -
Amano Returns
to the AGA Annual Convention
Nov 2004 -- Baltimore

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