Biological filtration provides an environment that breaks down organic waste such as excess food and feces. It decomposes and detoxifies the debris.
Mechanical Filtration cleans the water by mechanically trapping debris in filter floss, gravel or a foam filter cartridge.
Chemical filtration uses chemical filtrates to clean water by removing odors and discolorations. Use chemical filtrates such as activated carbon, ammonia absorbents and water softeners.
Different fish need different types of filters. The following chart describes the various types of filters and which types of filtration they provide.
| Filter Type |
Description |
Filtration Type |
PETCO Suggestions |
| Box (Corner) Filter |
- Usually a plastic box, which contains filter media that traps debris, while the carbon removes discoloration and odor from the aquarium water
- Placed in the back corner of the aquarium
- Powered by an air pump
|
√ Biological √ Mechanical √ Chemical |
|
| Undergravel Filter |
- Best all-around filter for any aquarium
- Simple
- Inexpensive
- Provides aeration
- By drawing "oxygen-rich" water through the gravel, this filter promotes the growth of bacteria in the gravel to break down fish waste and leftover food (biological filtration)
- Air pump or powerheads are used to run this type of filter (reverse flow systems)
|
√ Biological √ Mechanical Chemical |
|
| External Power Filter |
- Uses a built-in water pump for power
- Usually provides mechanical filtration and chemical filtration
- Collector of wastes (mechanical filtration)
- Must be periodically emptied and cleaned
- Usually moves more water than air-driven filters
- Many newer power filters also add a site for biological filtration to occur (may be in the form of a wheel or sand or some other method)
- May also be used in conjunction with undergravel filter
|
√ Biological √ Mechanical √ Chemical |
|
| Sand Filter |
- Variation of External Power Filter and uses all the same mechanisms
- Sand in this unit provides biological filtration
- The media (carbon, floss, or foam) must be changed periodically (sand media can remain constant)
|
√ Biological Mechanical Chemical |
|
| Internal Power Filter |
- Driven by electricity
- Placed inside the aquarium
- Holds a limited amount of mechanical and chemical filter material
- Designed to be space-saving
|
Biological √ Mechanical √ Chemical |
|
| Canister |
- Very efficient filter
- Has a large plastic container filled with different kinds of filter material
- Recommended for larger aquariums or for smaller aquariums that house a large number of fish
|
√ Biological √ Mechanical √ Chemical |
|