Thanks for your comments on my draft, they are very helpful!
"Peter Pan" wrote in message
...
LMAO.. Funny
"Wayne Sallee" wrote in message
ink.net...
Is this the book report that you are giving to your first
grade teacher?

Wayne Sallee
Wayne's Pets



Guayni; SAHS wrote on 12/22/2006 8:14 PM:
Nitrates in Sal****er Aquariums
By Jaime Rivera-Sierra, www.guayni.com





Belief it or not, Nitrogen (N) and Phosphorous (P) are
limiting
nutrients in the oceans. This means that producers such as diatoms and
other algae can't produce more because of limited amounts of these two
elements. This is the way that the oceans had evolved over millions of
years. When there is an excess of N and P, the algae bloom causing red
or
green tides. This phenomenon instead of being helpful to the ocean's
inhabitants results detrimental by disrupting the entire food chain and
the
ocean's equilibrium. In open waters this should be avoided at all
costs.



On this paper I will discuss the effects of excess nitrogen
in
sal****er aquariums in various forms.



Nitrogen in a sal****er aquarium is present in four
different
forms. I have to emphasize that it enters your aquarium in the form of
food.



The most stable form of nitrogen in an aquarium is in the form of
living
tissue. Every living organism incorporates nitrogen to each and every
cell
for many reasons. The amount of nitrogen not needed for flesh is
excreted
back to the water in the form of ammonia.



The ammonia enters the water column in the form of urine, feces or
gills'
secretions. A high level of ammonia in an aquarium is toxic to fish
and
disrupts the other life cycles of your aquarium's residents. Ammonia
is
the
most toxic and unstable of the four nitrogen forms.



Once Ammonia enters the water column either evaporates as
ammonia gas (NH4+) or gets recycled in the nitrogen cycle. This task
is
performed by nitrifying bacteria that turns ammonia (NH3) to nitrites
(NO2).
In the nitrite form, N stays unstable replacing oxygen in breathing and
affecting in many ways the metabolism of your fish. Although not as
unstable as ammonia, nitrites will deteriorate your aquarium and can
kill
your fish if levels exceed a tolerable margin. High levels of nitrites
must
be avoided.



The nitrifying bacteria continue to process
nitrogen-containing
compounds turning nitrites to nitrates (NO3). At this point nitrogen
is
at
its lowest unstable condition becoming accessible to plants. In the
nitrate
form, algae and other plants reincorporate nitrogen into its tissue.
In
open waters, these plants are eaten by consumers restarting the cycle
again.
On the other hand, in a closed system as your aquarium, nitrates
accumulate
to detrimental levels.



An excess accumulation of nitrates may cause some problems to your
system as
it remains unstable. NO3 can't be reduced again by nitrifying bacteria
and
has to be removed from the tank. There are different methods to
achieve
this task. The most common procedure is known as a "water change".
Using
this technique, aquarists remove water from the tank and replace it
with
waters with low nitrates levels, thus diluting the water column. This
method is costly and tedious requiring periodical water changes that
may
range from twice a year to twice a week and from 10% to 20% of the
water
column. Another good method of extracting nitrates from the water is
by
harvesting plants that incorporated nitrates to its tissue. Since
under
this conditions N is not a limiting nutrient, plants will bloom and
algae
will cover your tank making it easy to remove. The more plants you
harvest,
the less need for periodical water changes. Each plant you extract
contains
nitrogen built into its living tissue from the most available source,
NO3.



In summary, nitrogen is an element that needs to be controlled in your
system. The nitrogen cycle works only one way. The nitrogen in your
system
enters in the form of food, this food is taken by your fish and the
excess
is redirected to the water column in the form of ammonia. Nitrifying
bacteria turns ammonia to nitrites and then to nitrates. Once the
nitrogen
is in the form of nitrates the only way out is mechanical. An aquarist
has
to make a decision to extract nitrates directly from the water by means
of
water changes or by harvesting plants that utilized nitrates as
nutrient.



References;



Dakin, N. 2003. Complete Encyclopedia of the Sal****er Aquarium



Mitsch, W.J. and J.G. Gosselink. 2000. Wetlands 3rd Ed.



Rivera-Sierra, J. 1992. Impacto Ambiental Acumulativo Del Desarrollo
Costanero En El Sector Playita De Salinas, Puerto Rico