Aquariums are more densely populated than natural bodies of water. The excessive amount of ammonia produced requires the use of biological, mechanical, and chemical filtration systems. Biological filters provide extra surface area containing ammonia eating bacteria for water to flow over. Mechanical is the use of a filter medium that captures solid particulates from the water for manual disposal. Chemical filters, usually carbon and plants, help to remove already dissolved waste compounds. There should also be partial water changes done to ensure that build up within the system does not occur. There are numerous types of materials used for filtration. The most common are wool/nylon, synthetic sponges or foams, silicon products, and gravel. Most filters utilize multiple layers of these materials and serve both biological and mechanical filtration purposes. Activated carbon and zeolite filters then serve chemical filtration needs for any remaining waste compounds.
| Filter Type | Cost Range | Maintenance Level | Effectiveness of Filtration | ||
|---|---|---|---|---|---|
| Mechanical | Chemical | Biological | |||
| Corner Filter
|
Low | Medium | Low | Low | Low |
| Sponge Filter
|
Low | Low | Low | Low | Low |
| Under Gravel Filter
|
Low – Medium | High | Low | Low | Medium |
| Power Filter (HOB)
|
Low – Medium | Low | Medium | Medium | Low |
| Power Filter with Bio Wheel
|
Low – Medium | Low | Medium | Medium | High |
| Canister Filter
|
Medium | High | High | High | Medium |
| Canister Filter with Bio Wheel
|
Medium | High | High | High | High |
| Wet/Dry Filter
|
High | Low | Medium | Medium | High |
