[APD] Re: Is the W/G figure valid for a 10 gallon tank?

[Bill Wichers <billw at waveform_net>]

> Presently, I'm leaning toward T8 fluorescents. I believe the ones that are
> the proper length are 15 watts (F15T8 ?). Any comments pro or con about
> choosing these bulbs would be appreciated!

Don't use them. The small (13 watt) PCFs are much better for this 
application. A 10 gallon hood's lightbar is not really large enough to 
accommodate enough T8 lights or a good reflector. Two of the AH Supply 13 
watt PCFs in their reflector is a much better fit and will provide a good 
amount of light for that size tank (about 26 watts, and a very efficient 
reflector). I would suggest using a commercially made light hood and 
modifying the lightbar using the AH Supply dual 13 watt PCF bright kit. 
It's inexpensive to do this, very easy (maybe an hour to complete the 
modifications, using just a wire stripper, screwdriver, and maybe a small 
drill), and the results look very professional since the enclosure is a 
commercially made hood. The bright kit also has the added benefit of 
bringing all the pieces you need together in one spot.

> Now, if one uses the 2 W/G figure as the threshold between low light and
> high light, one T8 would certainly qualify as low light, and that's what the
> standard off-the-shelf fluorescent hoods have.

You get a 15 watt T8 in a standard 10 gallon hood if I remember correctly 
(and the same for a 20 gallon). The typical reflector is a piece of white 
plastic that is far from optimum. Usually the smaller tanks need a higher 
watt/gallon ratio according to what has been said on the list (I haven't 
really worked much with tanks <20 gallons except for a few 5 and 2.5 gallon 
grow-out tanks -- and I use 13 watt PCFs on the 5 gallon tanks, BTW).

> However, it doesn't really seem like two of these bulbs (total of 30W) would
> be bright enough.

It also won't fit very well -- you'll block a lot of the top of the tank. 
Using a good reflector, you would probably cover at least 2/3 of the tank 
surface with your light fixture if you use T8s, leaving little room for 
filters or feeding.

> Is the W/G figure valid for a 10 gallon tank?

There is some info in the archives on this, but with 10 gallons and below 
it seems to be necassary to use more watts/gallon to achieve the desired 
results.

> Anyone had any luck overdriving a single one of these bulbs?

You probably could, but I don't think it would be worth it. PCFs are cheap 
in the small sizes, and last longer than an overdriven T8 is likely to. 
With a 10 gallon tank you will need to concentrate on physically fitting 
enough lighting over the tank due to the small space you have to work in. 
If you have several 10 gallon tanks in a row, a shoplight would work well, 
but for a single tank you will be limited in what is available on the 
market to work with.

     -Bill


*****************************
Waveform Technology
UNIX Systems Administrator

_______________________________________________
Aquatic-Plants mailing list
Aquatic-Plants at actwin_com
http://www.actwin.com/mailman/listinfo.cgi/aquatic-plants