SUNSUN HW-604B External Canister Filter

SunSun HW 604B External Filter for Compact Multi-Stage Aquarium Filtration

The SunSun HW 604B External Filter is a practical external canister filter for aquariums that need clean water, steady circulation, and flexible filtration media space. Designed for tanks around 60–75cm and suitable for approximately 125–250 litres depending on stocking level, it offers a strong 800 litres per hour flow rate while using only 14W of power. Its compact external design helps keep the aquarium display neat by placing the filtration system outside the tank.

This filter is built for multi-stage aquarium filtration and can handle mechanical, biological, and chemical media combinations. The supplied filter pads help trap visible debris and suspended particles, while the extra internal space above and below the pads can be used for ceramic rings, bio balls, activated carbon, fine floss, or other compatible media. This gives aquarists better control over water polishing, beneficial bacteria support, and overall filtration performance.

The SunSun HW 604B is suitable for freshwater and marine aquariums and works well for planted tanks, community fish tanks, shrimp tanks, betta setups with controlled outlet flow, small cichlid tanks, and medium aquascapes. It can also be used as a pre-filter for other SunSun canister filters, helping trap debris before water reaches the main filter and reducing maintenance load on larger filtration systems.

Specifications of SunSun HW 604B External Filter

• Product Type: External canister aquarium filter
• Model: HW 604B
• Brand: SunSun
• Flow Rate: 800 litres per hour
• Pump Power: 14W
• Voltage: 220V / 50Hz
• Recommended Aquarium Length: Around 60–75cm
• Recommended Aquarium Volume: Approximately 125–250 litres depending on stocking and maintenance
• Filtration Type: Mechanical, biological, and chemical filtration
• Maximum Head Height: Approximately 1.5m
• Hose Size: 16mm
• Product Dimensions: 6.5 inch L × 6.5 inch W × 11 inch H
• Alternative Listed Dimensions: 5.7 inch L × 5.7 inch W × 10 inch H
• Metric Size Reference: Approximately 230mm L × 195mm W × 365mm H
• Package Weight: Approximately 1.75kg listed product weight
• Package Dimensions: 25cm × 34cm × 30cm
• Suitable Water Type: Freshwater and marine aquariums
• Included Accessories: Filter pads, hoses, inlet and outlet parts, and required setup components
• Additional Media Space: Space available above and below filter pads for extra media
• Pre-Filter Use: Can be used as a pre-filter for other compatible SunSun canister filters
• SKU: HW604b

How to Use This External Canister Filter

1. Place the SunSun HW 604B below or beside the aquarium on a stable, level surface where it can be accessed easily for cleaning.
2. Open the filter body and position the supplied filter pads inside the canister.
3. Add extra media such as ceramic rings, bio balls, activated carbon, or filter floss in the available space above and below the pads if required.
4. Attach the inlet and outlet hoses securely, making sure all connections are tight to avoid air intake or water leakage.
5. Position the inlet pipe inside the aquarium where it can draw water efficiently without pulling in substrate, floating plants, or large debris.
6. Install the outlet pipe or spray bar so filtered water returns evenly to the aquarium and creates suitable surface movement.
7. Fill the filter with water before starting, then switch on the power to begin siphoning and circulation.
8. Check the filter after startup for leaks, trapped air, reduced flow, or unusual noise.
9. When using it as a pre-filter, connect it before the main compatible canister filter to trap debris before water reaches the primary filter media.

Care & Maintenance Tips

• Rinse filter pads in removed aquarium water during maintenance to preserve beneficial bacteria.
• Clean mechanical pads when flow reduces or visible waste builds up inside the filter.
• Add biological media such as ceramic rings or porous bio media for stronger long-term filtration.
• Use activated carbon or chemical media only when needed for water polishing, odour control, or specific water treatment purposes.
• Do not replace all filter media at the same time, as this may disturb the aquarium’s biological balance.
• Inspect hoses and inlet strainers regularly to prevent clogging from plant leaves, fish waste, or algae buildup.
• Clean the impeller and pump area periodically for smooth, quiet operation.
• Always ensure the lid and clips are locked properly after cleaning to avoid leaks.
• Keep the filter running continuously to support stable oxygen movement and beneficial bacteria activity.