A filter fits in a fish tank in various configurations, primarily determined by its type, with some placed inside the aquarium, others hanging externally, and certain high-capacity systems positioned below the tank. The fit is designed to efficiently circulate and clean the tank water.
Understanding Filter Placement Options
The placement of an aquarium filter is crucial for its effectiveness and the overall aesthetic of your tank setup. Different filter types have distinct fitting mechanisms and locations.
1. Canister Filters: External and Sub-Cabinet Placement
Canister filters are a popular choice for larger tanks due to their efficiency and customizable media options. As per their design, canister filters are positioned below the aquarium, usually inside the cabinet stand. This external placement keeps the filter body out of sight, contributing to a cleaner tank aesthetic.
- How they fit:
- Intake Tube: An intake tube extends from the filter up into the aquarium, drawing water from the tank.
- Filter Body: The main filter unit, containing various filter media (mechanical, chemical, biological), sits on the floor or a shelf inside the cabinet stand directly beneath the tank.
- Return Tube: A separate return tube extends from the filter back into the aquarium, pumping the filtered water back into the tank.
- Tubing Connections: Hoses connect the intake and return tubes to the filter unit, running discreetly through openings in the tank stand.
This setup allows for powerful filtration without occupying valuable space within the display tank itself.
2. Hang-On-Back (HOB) Filters: External and Above-Waterline Placement
Hang-On-Back (HOB) filters are common for beginner to intermediate setups due to their ease of installation and maintenance.
- How they fit:
- The main filter body hangs on the back rim of the aquarium.
- An intake tube extends down into the water inside the tank.
- A waterfall-like return or spout directs filtered water back into the tank from the filter's external chamber.
- They typically require minimal clearance behind the tank.
3. Internal Filters: Submerged Placement
Internal filters are compact units ideal for smaller tanks or as supplementary filtration.
- How they fit:
- The entire filter unit is submerged within the aquarium water.
- They are usually secured to the tank wall using suction cups.
- Water is drawn in from the tank, passed through the filter media, and then expelled back into the tank through an outflow nozzle.
4. Sump Filters: Advanced Sub-Tank Filtration
Sump filters are sophisticated filtration systems, often found in larger, more complex aquarium setups, especially marine tanks.
- How they fit:
- A sump is essentially a secondary, open-top tank located below the main aquarium, typically within the cabinet stand.
- Water overflows from the main tank, travels down plumbing into the sump (where filtration media, heaters, protein skimmers, etc., are housed).
- A return pump then sends the filtered water back up to the main display tank.
- This system requires custom plumbing and sufficient space in the stand.
Filter Placement Comparison Table
| Filter Type | Primary Placement | Key Fitting Mechanism | Ideal For |
|---|---|---|---|
| Canister Filter | Below the aquarium, inside a cabinet stand | Intake/Return tubes connecting to external filter unit | Medium to large tanks, custom setups |
| Hang-On-Back (HOB) | Hangs on the back rim of the aquarium | Intake tube inside, filter body outside | Small to medium tanks, easy setup |
| Internal Filter | Fully submerged inside the aquarium | Suction cups for attachment to tank wall | Small tanks, quarantine, supplementary |
| Sump Filter | Below the main tank, typically in a cabinet | Overflow plumbing from tank to sump, return pump | Large, complex, or marine aquariums |
Choosing the right filter type and understanding its fitting mechanism is essential for maintaining a healthy and clear aquatic environment. Each method offers unique benefits in terms of space utilization, filtration capacity, and accessibility for maintenance.
