Filters and pumps are an essential component of your aquarium for two reasons: First, they aerate the water, and second, they remove harmful debris from the water. Though fish don't breathe air, they need oxygen to survive and are sensitive to nitrogen. Increased levels of nitrogen created by garbage, excrement, or a dead fish in a tank could be fatal to an otherwise healthy fish.
To figure out what kinds of filters you need, first pick your fish, then your tank,
The Three Types of Filters
The main types of filter systems available on the market are biological, mechanical, and chemical. Many of the newest types of filtration systems use one or more of the following methods for filtration to improve effectiveness and user convenience. They come in both internal and external styles.
* Canister Filter: Very efficient, good for large aquariums with many fish. Uses all three filtration methods.
* External Power Filter: Powered by a water pump. Uses all three methods of filtration. Needs periodic cleaning and emptying. Can be combined with an under gravel filter for optimum filtration.
* Internal Power Filter: Uses electricity to run a mechanical and chemical filter. Space-saving.
* Corner/Box Filter: Uses all three filtration methods and it is powered by an air pump.