Filtration
Filtration is a key factor for a clean and healthy aquarium. Most people
stock their tanks at levels far above what one would find in nature (in relation
to water volume). The biological waste products emitted by aquarium
inhabitants must be effectively removed and metabolized before they become
toxic to the inhabitants of the tank. Aquarium filters are available in various
configurations and should provide mechanical, biological and chemical filtration,
as well as oxygenation.
Mechanical
The most basic definition of mechanical filtration is the removal of solid
particles from the aquarium water . This is an essential form of filtration.
Most filter media mechanically filter the water to some degree. Mechanical
filter media, which is very fine (like paper cartridges), will trap larger
amounts of debris but will also plug up more quickly. You should clean your
filters regularly to gain the most benefit from mechanical filtration. This
will help support superior oxygen levels, help keep water conditions stable
and reduce nitrate accumulations. Mechanical filtration will not remove ammonia,
bacteria, algae or debris trapped by the gravel or plants. Some examples
of mechanical filter media are filter floss, sponges and paper cartridges.
Chemical
Basically, chemical filtration is the removal of dissolved wastes from the
water. It changes specific water characteristics. It can remove chlorine,
eliminate medications after disease treatments or neutralize heavy metal ions.
It can make changes in hardness and pH levels. This form of filtration
is particularly useful when you know what's in the water already (done through
the use of basic test kits). Some examples of chemical fi lter media are: carbon, zeolite or
protein skimming.
Biological
Biological filtration is accomplished by various strains of bacteria. There
are several sources of waste produced in aquariums. Fish generate waste as
they pass water over their gills and poop. Plants shed leaves as they grow.
Beneficial bacteria known commonly as nitrifying bacteria, prefer living in
the filter system. Enhanced levels of oxygen exist due to constant incoming
water, while the biological filter media provide an excellent environment
for these desirable bacteria. Nitrifying bacteria consume two very harmful
compounds, ammonia and nitrite, as an energy source, and produce nitrate,
a relatively harmless by-product. Nitrate can be easily controlled through
regular water changes and is also used by plants as a food source.
The Nitrogen Cycle (see chart and further explanations on this page) refers
to the conversion of toxic nitrogenous compounds, ammonia and nitrite to nitrate.
Water chemistry, temperature, pollutants and other factors can affect the
performance of nitrifying bacteria. Maintaining stable temperature, pH and
water quality is important for all tank inhabitants, even for those that are
invisible to the human eye, specifically, bacteria.
For new aquariums, ensure the following:
Avoid overfeeding
Regular testing of Ammonia, Nitrite, & pH.
Stock the aquarium slowly
Regular removal of organic debris (dead plant leaves, waste in the gravel,
etc.).
Use a dechlorinator and/or chloramine remover with all water changes (removes
toxic elements).
Filtration systems
There are many choices of filters you can use on your aquarium. Personally,
I find ones that are easiest to clean the best option. The choices include
powerheads, air pumps, hang-on
power filters (e.g. Aquaclear), canister filters (e.g. Fluval) , underwater filters (internal) (e.g.
UGF) and external filters. These systems represent a common choice for most
aquarium keepers. The general principle involves the intake of aquarium water
via a siphon that results in filtration through one or more filter media.
The return flow is directed at the surface to provide oxygen.
Fresh water aquariums generally require a minimum water turnover rate of
approximately four times an hour. Marine aquariums usually do best with water
turnover rates of 7 to 10 times per hour. Exceptions do exist with respect
to the livestock being kept. So you basically have to figure out what size
tank you will be putting the filter on to help decide what size of filter
you will need. (Most filters have suggested tank sizes on them). In general,
it is best to select a system(s) which provides somewhat more than the minimum
rate. This will help compensate for declining flow rates as the filter system
accumulates debris. You can also use a couple of slightly smaller filters
to act as backups to your main filter and allow you to clean one filter completely.
That way you have one filter still full of nitrifying bacteria. You would
then clean that filter on your next tank cleaning instead.
Back to the Basic Guide
Temperature
Nitrogen Cycle
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