The Nitrogen Cycle Part of the Ecosystem of a Freshwater Aquarium

The nitrogen cycle is a natural process in anyred or bloodshot eyes, red inflamed gills, or red
aquarium. It begins as soon as you add the first fishstreaks on the sides of your fish. Ammonia levels of
to the tank. Their waste products include ammonia,0.25 to 0.5 parts per million (ppm) can stress your
which starts the nitrogen cycle. During the initial setupfish, while above 1.0 is considered lethal. Although it's
period, it is important that you test the water qualitybest to let the beneficial bacteria eat the ammonia,
daily, so that you can watch your tank progresscontinuing the nitrogen cycle, if the levels get too
through the stages of the nitrogen cycle.high you should change 15 to 25 percent of the
In addition to simply adding fish to the aquarium,water to reduce ammonia levels. Reducing the
there are other ways to jump-start the nitrogenamount of food you are feeding will reduce future
cycle. Those with saltwater aquariums can add liveammonia levels.
rock to begin the process. If you are setting up aWithin two weeks of introducing the first fish to
freshwater tank, it is possible to add a cup of gravelyour new aquarium, a beneficial bacteria will start to
from an established tank. Although it will contain theeat the ammonia. This nitrifying bacteria converts
beneficial bacteria necessary for the nitrogen cycle, itammonia into nitrites. Your tank may become cloudy
may also contain unwanted bacteria or parasites, soduring this stage in the process, as the bacteria
this method should be used with caution.multiply quickly to eat the excess ammonia. At this
When your new aquarium is first set up, it'spoint, nitrites should begin appearing on your water
important not too add too many fish. Adding tootest results.
many fish results in high levels of waste, which yourIn another week or two, you will start to see
new tank ecosystem may not be able to handle. Asincreasing nitrate levels on the water test strips.
the ammonia levels spike, your fish could die. In fact,Moderate levels of nitrates cause no harm to your
many experienced fishkeepers recommend beginningfish. They can build up, however, especially if you are
with a few inexpensive fish to begin the nitrogennot diligent about changing the water in the tank. If
cycle if you plan to keep exotic tropical fish in thelevels go above 80 to 100ppm, a water change can
aquarium. This way, if your first nitrogen cycle doeshelp increase the water quality in the aquarium. In
not go as planned, you won't kill off an expensiveaddition to regular water changes, live plants can also
and rare fish.remove nitrates from the aquarium environment.
As you add fish to the aquarium, ammonia levels willThe nitrogen cycle is a very important process in
start to rise immediately. All of the food you put intoyour aquarium. You can expect the full cycle to take
the tank will eventually be converted into ammoniaanywhere from three to six weeks to become
by your fish. You can expect ammonia levels toestablished. This step is crucial if you want the
fluctuate as the aquarium ecosystem settles into aaquarium to be healthy, and it must be monitored
routine. However, ammonia buildup is dangerous forclosely with water test kits.
your fish. Signs that the ammonia is too high include