Like all living creatures, fish give off waste products. These
waste products break down into ammonia (NH3), which is highly toxic
to most fishes. In nature, the volume of water per fish is extremely
high, and waste products become diluted to low concentrations. In
aquariums, however, it can take as little as a few hours for ammonia
concentrations to reach toxic levels.
How much ammonia is too much? The quick
answer is: if a test kit is able to measure it, you
have too much. In aquaria-speak, the "nitrogen
cycle"' (more precisely, the nitrification cycle)
is the biological process that converts ammonia into
other, relatively harmless nitrogen compounds. Fortunately,
several species of bacteria do this conversion for us.
Some species convert ammonia (NH3) to nitrite (N02-),
while others convert nitrite to nitrate (NO3-). Thus,
cycling the tank refers to the process of establishing
bacterial colonies in the filter bed that convert ammonia
to nitrite and finally into nitrate.
The desired species of nitrifying bacteria
are present everywhere. Therefore, once you have an
ammonia source in your tank, it is only a matter of
time before the desired bacteria establish a colony
in your filter bed. The most common way to do this is
to place a few hardy and inexpensive fish in your aquarium.
The fish waste contains the ammonia on which the bacteria
live. Do not overfeed them! The bacteria replicate slowly,
and adding in too much food can cause the process to
take longer, with the possible result being the loss
of fish. During this time, we recommend feeding every
other day. Some suggested species include: Zebra Danios
and Black Skirt Tetras for fresh water tanks and Damsels
for salt water tanks. Note: Do not use feeder goldfish.
Although cheap, they create large amounts of ammonia,
which a new tank is not equipped to handle.
Salt Water Reef tanks have
these bacteria present in the live sand and / or live
rock in high concentrations, therefore the cycling time
is shortened.
During the cycling process, ammonia levels
will go up and then suddenly plummet as the nitrite-forming
bacteria (Nitrosomonas) take hold. Because nitrate-forming
bacteria do not even begin to appear until nitrite is
present in significant quantities, nitrite levels increase
dramatically (as the built-up ammonia is converted),
continuing to rise as the constantly produced ammonia
is converted to nitrite. Once the nitrate-forming bacteria
take hold, Nitrobacter bacteria start to convert Nitrite
into Nitrate. As nitrite levels fall, nitrate levels
rise, and the tank becomes fully cycled.
Your tank is fully cycled once nitrates are being produced (and
ammonia and nitrite levels are zero). To determine when the cycle
has completed, buy appropriate test kits and measure the levels
yourself. As a customer of Austin Aquariums, feel free to bring
your water to us for a free test. The cycling process normally takes
anywhere from 4-6 weeks. It is sometimes possible to speed up the
cycling time by adding products that contain these bacteria. Some
examples of these products are Hagen's “Cycle”, Fritz-Zyme
#7 (Fresh Water), FritzZyme #9 (Salt Water) and Turbo Start (Fresh
or Salt) from Fritz.
Warning: If you loose fish during this process, AVOID
THE TEMPTATION TO GET MORE FISH UNTIL AFTER YOUR TANK HAS FULLY
CYCLED! You cannot introduce fish in the middle of the Nitrogen
cycle. They cannot adjust their bodies to the rapidly increasing
levels of Ammonia and Nitrite and they will die within days of introduction.
High levels affect the red blood cells of fish causing internal
injuries and most likely, death. More fish means more ammonia production,
increasing the stress on all fish and the likelihood of additional
fish loss.
Once your tank is cycled and you begin to add fish, remember to
do regularly scheduled water changes. Failure to do water changes
can result in your water becoming discolored (brown, yellow, green
or a cloudy white) and your fish becoming stressed out and more
susceptible to disease. We recommend purified water (like our environmentally
friendly method, or the more wasteful Reverse Osmosis method) for
water changes. Purifying the water removes heavy metals, toxins,
organic compounds and other “nastiness” from the water,
making it very clean. If you must use tap water, be sure to use
products that remove Chlorine and Chloramines, as these chemicals
are safe for human consumption, but are not safe for fish. They
can kill fish within an hour if not removed. If you are running
a Salt Water Reef tank you must keep a close eye on your Nitrate
levels as they are harmful to corals and invertebrates as well as
fish.
Knowledge and patience are the keys to having a successful
aquarium. Be patient while your tank is cycling, take the time to
read and learn more about the fish you intend to keep. Keeping an
aquarium is a commitment. You get out of it what you put into it.
You are creating a contained environment that simulates the fish's
natural environment and great care should be exercised to ensure
everything is as close to the natural conditions as possible These
things include but are not limited to proper temperature, high quality
protein foods, stable water conditions, adequate lighting and filtration.
