Re: [APD] Help With My New Tank!! -- or - Burning to find the light

["S. Hieber" <shieber at yahoo_com>]

--- Shalom Levytam <shalominc at yahoo_com> wrote:

> . . . I will be building a sump in the future but for now
I
> think the tank will be setup with either the Magnum
> 350 Pro or Eheim 2215.  Which would you recommend?

Just about any filter, and any type of filter will serve
you well with a well planted aquarium. They aren't fussy
about the kind of filter. Lots of air/water mixing tends to
shed CO2 so a trickle filter will tend to shed more CO2
than, for example, a canister filter with the output below
the water surface. Eheims cost more and they have a great
reputation for reliability. Otoh, some very good aquatic
gardeners have used the Magnum without complaint for years.
Take your pick.

> 
> I took your advice and got a hold of that book. 
> Thankfully, they had it at the library!!  It, along
> with another 2 books I found, have convinced me to use
> soil as my base substrate.  If its potentially better,
> and cheaper, the extra work is well worth it.  

Soil underlayment is a way to provide nutrients without
them all getting into the water column in one fell swoop.
Just be careful when uprooting plants. I think that's the
biggest complaint about soil underlayment -- when you stir
up a bunch of it into the water.

> 
> I don't know if anyone is familiar with Home Depot but
> does anyone know of a specific soil that has worked
> well? 


If you have Diana's 2nd edition, she might make some
specific recs about commercial soil products. In the first
edition, as I recall, she suggested going into the backyard
and scoping up some soil. some folks like to let "backyard"
soil age in water for a week or so so that any sudden
changes in it's behavior can be triggered before you set up
your tank. I'd put a good 3" of gravel over the thin soil
layer.
> 
> Finally, I am glad to hear my spotlight idea is
> feasible.  I also read today that metal halides are
> essentially the same as halogen lights.

I don't know what they were refering to in terms of
similarities but there is a very significant diff between
halogen incandescent lamps and MHs. In terms of how they
operate, as light bulbs go, they are extraordinarily diff.
Incadescents illuminate by running electrical current
through a tungesten filament, which makes the filament get
so hot that it incandesces (it glows). They are roughly 5%
energy efficient over their life -- about 95% of the input
energy goes out as heat rather than visible light. MHs otoh
are arc lamps and illuminate by running arcing an
electrical current across the space between two electrodes.
The mixture of gas in the bulb, and the amount of gas
pressure that develops, determines the spectrum given off
by the bulb. MHs are actually much more similar to
fluorescents in this regard -- fluorescents are also arc
lamps, but of course, there are diffs in how they operate
compared to MHs. MHs of the type useful for aquatic
gardening rather than parking lot lighting are about 35%
energy efficient. Getting enough light with incadescents
will end up shedding a terrific amount of heat, watt for
watt, compared to MHs or fluorescents. Incadescent bulbs
are cheap but generally only practical for small very low
light tanks, and even then small fluorescents are, imo, a
much better choice.

>  Would
> numerous halogen lights be able to provide the type of
> light I require.  (No doubt I could get the intensity
> necessary). 

You'll need to burn about 5-7 times as many watts of
incandescent than MHs -- how's your air conditioning; how's
your electric bill? How much room do you have over your
aquarium for lamps?

Halogens are usually rated as about 20-30% more efficient
than ordinary incadescents --which nets out to about 6-5%
energy efficient compared to a regular incandescent, which
are more tyupically about 3-4% efficient. That is still a
far cry from fluorescents and MHS which are about 500-700%
more efficient than regular incandescents. The reason
halogen incandescents are slightly more energy efficient
than regular incandescents is for two reasons. First,
halogens, because of the prescence of a halide gas in the
bulb tend to redeposit back onto the filament the material
that evaporates from the filament in normal burning. Other
things being equal, this allows the filament to last
longer. But importantly, it means that the bulb's inner
glass surface gets coated with that grayish balckish film
more slowly and for a given period of bulb life, less light
is blocked the coating on the inner bulb surface. Second,
due to the prescence of the gas and the smaller bulb
envelope, higher pressures develop inside the bulb which
makes the filament burn hotter at a given current and give
off a bit more light -- although this higher temp tends to
counteract the life prolonging effects on the filament of
the halide gas. The redspositing helps prolong but the
higher filament temp tends to shorten filament life.
Manufacturers can vary the amounts but generally the best
incandescent will be no better than about 5-6% energy
efficient. Arc lamps, otoh, range from about 30 to nearly
90% efficient. The really high efficiency bulbs are
extremely narrow spectrum bulbs that are used for certain
industrial applications but aren't suitable for planted
aquaria. Bulbs with spectra suitable for aquaria range
about 35% efficient.

Hope that helps clear things up a bit,
Good luck, good fun,
Scott H.

=====
It's the contest that started international competition in aquascaping
planted aquaria! AGA's 2004 Aquascaping Contest is open for entrees:

 http://showcase.aquatic-gardeners.org/2004.cgi

Novices and experts alike show their skills. Past winners have been
novices and experts, too. You can view all the entrees at The 5th AGA
Annual Convention. Details/Registration at www.aquatic-gardeners.org &
www.gwapa.org
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