Introduction
The SOBO External Fish Tank Filter is an efficient, wall-mounted filtration system designed to provide clear water and optimal oxygen levels for your aquarium. Featuring a three-in-one functionality, it combines mechanical, biological, and chemical filtration with an oxygen-increasing function and oil film removal. Its low-power design and ceramic axial silent rotor ensure a quiet operation, making it suitable for various environments, including bedrooms.

Image: SOBO External Fish Tank Filter mounted on an aquarium, highlighting its quiet and efficient operation.
Product Components
Familiarize yourself with the filter's components before assembly:

Image: Exploded view of the SOBO filter, showing all individual components.

Image: Detailed diagram of product accessories with numbered parts and their names for easy identification.
- Barrel body
- Barrel cover pump body
- Water outlet pipe
- Duckbill mouth
- Oxygen out regulation
- Effluent regulation
- Rain pipe
- Shock-absorbing bracket block
- Shock absorption bracket block cushion
- Cylinder stainless steel adhesive hook
- Inlet pipe
- Oil removal film
- Inlet extension pipe
- Water filter cover
- Filter material cover plate
- Filter material box
- Filter chamber partition
- Filter cotton
- Biochemical filter Cotton
- Suction Cup
Setup Instructions
- Assemble Filter Components: Refer to the 'Product Components' section and diagrams to correctly assemble the barrel body, pump body, filter material boxes, and filter media (white cotton, biochemical cotton). Ensure all parts are securely fitted.
- Install Inlet and Outlet Pipes: Attach the inlet pipe (11) and water outlet pipe (3) to the barrel cover pump body (2).
- Mount the Filter: Use the shock-absorbing bracket block (8) and cylinder stainless steel adhesive hook (10) to securely mount the filter to the rim of your fish tank.
- Adjust Water Level and Pipes:
- For standard use without an extension tube, the minimum cylinder height for the filter is 24cm.
- If your fish tank height is less than 24cm, the high fish tank pipe may need to be manually modified (sawn short).
- If using an extension tube (13), the water inlet should be at least 35cm deep. This ensures proper filtration and prevents debris from accumulating at the bottom.

Image: Diagram illustrating the correct setup of filter pipe fittings and water level requirements, including the use of an extension tube.
- Connect Power: Ensure the filter is correctly installed and submerged to the appropriate level before connecting it to a 220-240V power supply.
Operating Instructions
Filtration Process
The filter utilizes a multi-layer filtration system to purify water:
- Water enters the filter and passes through the white filter cotton for mechanical filtration, removing larger particles.
- It then flows through the biochemical filter cotton and other filter materials (e.g., ceramic rings) for biological filtration, where nitrifying bacteria break down harmful substances.
- The purified water is then returned to the tank.

Image: Diagram illustrating the multi-layer filtration process within the filter, showing the path of water through different media.
Flow Adjustment
The filter features an adjustable flow rate. You can arbitrarily adjust the water flow size according to the specific needs and size of your fish tank.

Image: Diagram highlighting the adjustable flow mechanism on the filter's outlet pipes.
Oxygen Increasing Function
The water outlet is equipped with an oxygen-increasing function, eliminating the need for an additional oxygen pump. The universal duckbill outlet and rain pipe outlet provide multi-angle oxygen waves to meet the oxygen demands of your fish tank. Gas volume can be regulated as needed.

Image: Diagram illustrating the oxygen increasing function, including the rain pipe and gas volume regulation.
Oil Film Removal
The filter includes a fast oil film removal feature. Oil film on the water surface can hinder oxygenation and photosynthesis of aquatic plants, impacting water quality and fish health. The floating head of the oil film remover can move up and down with the water level for effective treatment.

Image: Visual representation of the oil film removal function in action within an aquarium.
Maintenance
Regular maintenance ensures optimal performance and longevity of your filter.
- Filter Media Cleaning/Replacement: The filter comes with white filter cotton and biochemical filter cotton. These should be cleaned or replaced periodically to maintain efficient filtration. The frequency depends on the bioload of your tank, but generally, white filter cotton may need more frequent rinsing or replacement (e.g., every 1-2 weeks), while biochemical cotton can be rinsed in old tank water during water changes (e.g., monthly) to preserve beneficial bacteria. Do not change all filter media at once to avoid disrupting the nitrogen cycle.
- Impeller Cleaning: Periodically check and clean the impeller (part of the barrel cover pump body) to ensure smooth and quiet operation. Remove any debris or buildup.
- Pipe Cleaning: Clean the inlet and outlet pipes to prevent algae buildup and maintain optimal water flow.
Troubleshooting
- No Water Flow or Weak Flow:
- Check if the power is connected and the filter is turned on.
- Ensure the water level in the tank is sufficient for the filter's intake.
- Clean the impeller and check for any obstructions in the inlet/outlet pipes.
- Verify filter media is not excessively clogged and replace if necessary.
- Excessive Noise:
- Ensure the filter is fully submerged and properly mounted, avoiding contact with tank walls that could cause vibrations.
- Clean the impeller for any debris or wear.
- Check for air trapped inside the filter. Gently tilt the filter to release air bubbles.

Image: Diagram highlighting the quiet operation features, such as the rubber damping block and ceramic axial silent rotor, which contribute to a 'Bedroom Level Silent Experience'.
- Poor Water Clarity:
- Clean or replace clogged filter cotton.
- Ensure adequate biological filtration by maintaining healthy biochemical filter cotton.
- Check for proper water flow and circulation in the tank.
Specifications
The SOBO External Fish Tank Filter is available in three models:

Image: Visual comparison of SF-350F and SF-550F models, including their dimensions.
| Model | Power (W) | Flow (L/H) | Dimensions (cm) | Power Cord Length (cm) | Filter Volume (L) | Suitable for Fish Tank Size (cm) |
|---|---|---|---|---|---|---|
| SF-150F | 4W | 260L/H | 14 × 9 × 20 | 120 | 1.5 | 30-40 |
| SF-350F | 5W | 300L/H | 19 × 12 × 25 | 135 | 2 | 30-50 |
| SF-550F | 7W | 500L/H | 19 × 12 × 30 | 135 | 3 | 40-70 |
Voltage: 220-240V (This product is designed for 220-240V power systems only.)
Origin: Mainland China

Image: Specifications table for the SF-150F model, detailing its power, flow, dimensions, and suitable tank size.

Image: Specifications table for the SF-350F and SF-550F models, detailing their power, flow, dimensions, and suitable tank sizes.
User Tips
- Voltage Compatibility: Please note that this filter is designed for 220-240V power systems. Ensure your local power supply matches this requirement before use.
- Filter Media Volume: The SF-350F has a filter bin volume of 2 liters, and the SF-550F has a filter bin volume of 3 liters. These larger volumes allow for more filter materials, enhancing filtration effectiveness.
- Quiet Operation: The filter is designed for quiet operation, making it suitable for living areas. If you experience unusual noise, refer to the troubleshooting section.

Image: Diagram comparing the filter bin volumes of the SF-350F and SF-550F models, highlighting their capacity for filter media.
Warranty and Support
For any product-related inquiries, technical support, or warranty claims, please contact the seller or manufacturer directly. Keep your purchase receipt as proof of purchase.





