SUNSUN HW-304B External Canister Filter

SunSun HW 304B External Filter with UV for Large Aquarium Filtration and Clear Water Support

The SunSun HW 304B External Filter with UV is a powerful external canister filter made for aquariums that need strong circulation, reliable filtration, and added UV sterilization support. With an output of 2000 litres per hour, this filter is suitable for large aquariums up to around 150 gallons, depending on fish load, feeding routine, aquascape density, and maintenance schedule. It is a strong choice for freshwater tanks, planted aquariums, cichlid tanks, goldfish tanks, predator fish setups, and marine aquariums where consistent water movement and efficient filtration are important.

This aquarium external filter is capable of mechanical, biological, and chemical filtration, allowing users to create a customized media layout for their tank’s needs. Mechanical filtration helps trap visible waste and floating particles, biological filtration supports beneficial bacteria for a stable nitrogen cycle, and chemical filtration can be used to polish water or remove specific impurities when compatible media is added. The included filter pads, hoses, and setup parts make it easier to install, while the spacious canister design gives enough room for filter media customization.

The built-in 9W UV sterilizer adds an extra layer of water clarity support by helping reduce unwanted free-floating microorganisms and green water issues when used correctly. This makes the SunSun HW 304B especially useful for high-light planted aquariums, heavily stocked tanks, and larger aquariums where water clarity is a priority. The external design also keeps filtration equipment outside the tank, giving the aquarium a cleaner, more open look.

Specifications of SunSun HW 304B External Filter with UV

• Product Type: External canister aquarium filter with UV
• Model: HW 304B
• Brand: SunSun
• Flow Rate: 2000 litres per hour
• Approximate Flow Rating: 525 GPH
• Power Consumption: 55W
• UV Sterilizer: Built-in 9W UV
• Voltage: 220–240V / 50Hz
• Recommended Aquarium Capacity: Up to around 150 gallons
• Approximate Dimensions: 11 inch length × 17 inch height × 11 inch width
• Filtration Type: Mechanical, biological, and chemical filtration
• Suitable For: Freshwater and marine aquariums
• Included Accessories: Filter pads, hoses, inlet and outlet fittings, and setup parts
• Filter Media Note: Filter media is not part of the standard package except supplied filter pads
• Plug Option: 2 Pin Round or 2 Pin US Plug Flat, depending on available variant
• SKU: HW304B

How to Use This External Canister Filter

1. Place the SunSun HW 304B below or beside the aquarium on a flat, stable surface with enough space for hose routing and maintenance access.
2. Open the canister and arrange the supplied filter pads along with your selected aquarium filter media such as ceramic rings, bio media, activated carbon, fine floss, or other compatible media.
3. Use mechanical media at the first filtration stage to trap dirt, biological media in the main trays to support beneficial bacteria, and chemical media only when needed for water polishing or specific water treatment goals.
4. Connect the inlet and outlet hoses securely, making sure the hose ends are fitted tightly to prevent leaks or air intake.
5. Position the inlet pipe inside the aquarium where it can draw water efficiently without being blocked by plants, substrate, rocks, or decorations.
6. Install the outlet pipe or spray bar to return filtered water evenly to the aquarium and create suitable surface movement.
7. Fill the canister with aquarium water if required, close the filter head properly, and start the siphon or priming process before switching on the unit.
8. Plug in the filter only after water is flowing through the canister and check all connections for leaks, trapped air, or unusual vibration.
9. Use the UV sterilizer as needed for water clarity support, especially during green water issues or when extra control of free-floating microorganisms is required.

Care & Maintenance Tips

• Clean filter pads and sponge media using removed aquarium water to protect beneficial bacteria from chlorine damage.
• Do not replace all filter media at once, as this may disturb the biological balance of the aquarium.
• Inspect and rinse mechanical filter pads whenever water flow becomes weak or visible debris builds up.
• Use good-quality biological media in the trays for stronger long-term filtration performance.
• Replace chemical media such as activated carbon according to its usable life and only when required.
• Check the impeller chamber regularly and remove trapped sand, plant matter, or sludge for smooth operation.
• Clean inlet and outlet pipes periodically to prevent algae, biofilm, and waste from reducing flow.
• Ensure the canister lid and locking clips are seated correctly after every cleaning session to avoid leaks.
• Handle the UV section carefully during maintenance and never look directly at an active UV lamp.
• Keep the canister filter running continuously to maintain oxygen flow, filtration efficiency, and beneficial bacteria activity.