Introduction
This manual provides detailed instructions for the installation, operation, and maintenance of your fishkeeper 238GPH 5-Stage Canister Filter. Please read this manual thoroughly before use to ensure proper function and longevity of the product. This filter is designed for freshwater and saltwater aquariums up to 35 gallons.
Safety Information
- Always disconnect power before performing any maintenance or cleaning.
- Ensure all connections are secure to prevent leaks.
- Do not operate the filter if any part is damaged.
- Keep the power adapter and controller dry.
- This appliance is for indoor use only.
- Ensure the filter is placed on a stable, level surface below the aquarium water level as specified in the setup section.
Package Contents
Verify that all components are present before beginning installation.

Figure 1: Accessories List. This image displays all components included with your fishkeeper 238GPH Canister Filter, such as the filter unit, hoses, controller, and various filter media.
- Motor Unit
- Media Baskets
- Filter Case
- Inlet/Outlet Valves
- 2 x Hollow Quartz Balls (250g each)
- 1 x White Fine Sponge
- 4 x Black Coarse Sponge
- 2 x 1.5m Transparent Hose (16mm diameter)
- 6 x Strong Suction Cups
- Power Adapter
- Controller
- Outlet Pipe Assembly (Outlet pipe, Outlet Pipe Connector, Shower pipe, Universal water outlet nozzle)
- Inlet Pipe Assembly (Inlet pipe, Extendable inlet tube, Fish/Shrimp intake prevention screen, Filter screen)
Setup and Installation
Follow these steps for proper installation of your canister filter.
1. Prepare the Filter Media
Open the filter case and arrange the filter media in the baskets. The black coarse sponges should be at the bottom, followed by the white fine sponge, and then the quartz bio balls on top. Ensure all media is properly seated.
2. Assemble Inlet and Outlet Pipes
Video 1: fishkeeper aquarium canister filter Installation Steps. This video demonstrates the step-by-step process of assembling and installing the canister filter components.
- Connect the inlet and outlet pipes to their respective assemblies. The extendable inlet tube can be adjusted for tank depth.
- Attach the fish/shrimp intake prevention screen and filter screen to the inlet pipe.
- For the outlet, you can choose between the shower pipe or the universal water outlet nozzle.
3. Connect Hoses and Valves

Figure 2: Filter Head Details. This image highlights the flow control valves, 360-degree rotatable connectors, and the waterproof rubber ring for a secure seal.
- Attach the inlet/outlet valves to the corresponding ports on the filter head.
- Connect the transparent hoses to the valves. Cut the hoses to the desired length to fit your aquarium setup.
- Secure the inlet and outlet pipe assemblies inside the aquarium using the provided suction cups.
4. Filter Placement and Priming

Figure 3: Precautions for Use. This image illustrates the correct positioning of the filter canister and hoses, emphasizing the importance of a level surface and unkinked hoses.
- Place the filter canister on a level surface. The filter must be positioned 15.7 to 43.3 inches (40-110 cm) below the water surface of the aquarium for optimal performance.
- Ensure the hoses are not kinked or restricted, as this will impede water flow.
- The filter features a self-priming design. After connecting all components, simply add water to the filter case until it is full, then securely fasten all locking buckles. The filter will self-prime upon startup.

Figure 4: Filter Setup Example. This image shows a fully installed filter system, demonstrating its compact size and connection to an aquarium.
Operating Instructions
The fishkeeper canister filter features an intelligent controller for easy operation.
Controller Functions

Figure 5: Multi-Function Controller. This image details the buttons and indicator light on the intelligent controller.
- Power Button: Press to turn the filter On or Off. A blue light illuminates during operation.
- Flow Rate Buttons (+/-): Adjusts the water flow across 3 distinct levels. The filter defaults to maximum flow when powered on.
- Feeding Mode Button: Press to activate feeding mode. The filter will automatically pause for 5 minutes, allowing fish to feed without disturbance. The blue light flashes during feeding mode. After 5 minutes, the filter resumes operation automatically.
Flow Adjustment

Figure 6: Flow Rate Adjustment. This image demonstrates the visual difference between minimum, medium, and maximum flow settings.
In addition to the controller, you can fine-tune the flow using the inlet/outlet control valves, which offer stepless adjustment.
Feeding Mode

Figure 7: Feeding Mode in Action. This image illustrates how the feeding mode prevents food from scattering, ensuring fish can feed calmly.
The feeding mode is designed to provide a calm environment for your fish during feeding times, preventing food from being dispersed too quickly by the current.
Maintenance
Regular cleaning and replacement of filter media are crucial for maintaining optimal water quality and filter performance.
Cleaning and Replacing Filter Media
Video 2: Regularly Clean and Replace Filter Media. This video guides you through the process of disassembling the filter and cleaning its various media components.

Figure 8: 5-Stage Filtration System. This image details the layers of mechanical and biological filtration media and their function in maintaining water clarity.
- Frequency: Inspect filter media monthly. Cleaning frequency depends on tank bioload.
- Procedure:
- Disconnect the filter from power.
- Close the inlet/outlet valves and detach the hoses from the filter head.
- Unclip the locking buckles and remove the filter head.
- Carefully remove the media baskets.
- Rinse mechanical filter media (sponges) in old aquarium water to preserve beneficial bacteria. Do not use tap water directly, as chlorine can harm bacteria.
- Biological media (quartz bio balls) generally requires less frequent cleaning. Only rinse gently if heavily clogged.
- Replace sponges as they degrade or become too clogged to clean effectively.
- Reassemble the filter in reverse order, ensuring all seals are properly seated and buckles are secured.
Troubleshooting
If you encounter issues with your fishkeeper canister filter, refer to the following common problems and solutions:
- No Water Flow / Reduced Flow:
- Check power connection and ensure the filter is turned on.
- Verify that the inlet and outlet hoses are not kinked or obstructed.
- Ensure the filter is placed below the aquarium water level within the specified range.
- Clean or replace clogged filter media.
- Check for air in the system; re-prime if necessary.
- Leaking:
- Ensure the filter head is properly seated and all locking buckles are securely fastened.
- Check the main O-ring seal for damage or improper placement. Lubricate if dry.
- Verify that hose connections are tight and not cracked.
- Excessive Noise:
- Ensure the filter is on a level surface and not vibrating against other objects.
- Check for air trapped inside the filter; tilt gently to release air bubbles.
- Inspect the impeller for debris or damage. Clean or replace if necessary.

Figure 9: Quiet Operation Design. This image illustrates the internal components engineered for ultra-quiet performance.
Specifications
| Feature | Detail |
|---|---|
| Model Number | FK135-12W |
| Max Flow Rate | 238 GPH (900 L/H) |
| Power Consumption | 12W |
| Suitable Tank Size | 10-35 Gallons |
| Filtration Stages | 5-Stage (Mechanical & Biological) |
| Noise Level | Below 25dB |
| Item Weight | 6.78 pounds |
| Item Dimensions (L x W x H) | 14 x 11 x 9 inches (Package) |
| Target Audience | Fish |
| Specific Uses | Indoor Aquarium Filtration |
Warranty and Support
Your fishkeeper canister filter comes with a standard manufacturer's warranty. For specific warranty details, please refer to the product packaging or contact fishkeeper customer support. If you have any questions or require assistance, please visit the official fishkeeper website or contact their customer service department.