1. Product Overview
The fishkeeper FK065 Aquarium Filter is a versatile internal submersible filter designed to maintain optimal water quality in freshwater and saltwater aquariums ranging from 40 to 170 gallons. It features a powerful 16W motor with a flow rate of 265 GPH, providing efficient filtration and circulation. This unit combines multiple functions to create a healthy and clear aquatic environment.
Key Features:
- Crystal Clear Water: Effectively removes algae and contaminants for improved water clarity.
- Double Filtration System: Utilizes two sections of biochemical sponges for mechanical and biological filtration, breaking down waste and reducing odors.
- Quiet Operation: Operates below 40 dB, ensuring a peaceful environment.
- 4-in-1 Functionality: Acts as a filter, wave maker, water pump, oxygen supply, and circulator.
- Versatile Use: Suitable for both freshwater and saltwater aquariums.
- Tank Capacity: Ideal for tanks between 40 and 170 gallons.

Image: The fishkeeper FK065 Aquarium Filter operating in a fish tank, demonstrating water output and circulation.
2. Safety Information
Please read this manual thoroughly before operating the filter to ensure safe and correct usage. Failure to follow instructions may result in damage or injury.
- Always unplug the filter from the power outlet before performing any maintenance, cleaning, or when handling the unit.
- Ensure the filter is completely submerged in water during operation. Never run the pump dry.
- Do not use the filter if the power cord or plug is damaged.
- This appliance is intended for indoor use only, within an aquarium environment.
- Keep out of reach of children.
- Ensure the adjustable air inlet is positioned above the water surface if using the oxygen supply function.
- Do not use the filter below the minimum water level.

Image: Visual guide illustrating the correct water level for filter operation (above minimum) and an incorrect low water level scenario.
3. Setup and Installation
Follow these steps to properly install your fishkeeper FK065 Aquarium Filter:
- Prepare the Filter: Unpack all components and ensure no parts are missing or damaged.
- Attach Suction Cups: Securely attach the suction cups to the back of the filter unit.
- Position in Tank: Fix the suction cups onto a clean aquarium glass surface inside the tank. Ensure the filter is positioned vertically.
- Submerge Filter: Make sure the filter is completely covered with water before plugging it in.
- Connect Air Hose (Optional): If you intend to use the oxygen supply function, connect the air hose to the designated port on the filter.
- Position Air Inlet: Ensure the adjustable air inlet of the air hose is positioned above the water surface. This allows air to be drawn into the filter for aeration.
- Adjust Spout Direction: Rotate the adjustable direction spout to direct the water flow as desired for optimal circulation or wave-making.
- Power On: Once all steps are complete and the filter is fully submerged, plug the power cord into a suitable electrical outlet.

Image: Step-by-step visual guide for installing the filter, including attaching suction cups, submerging, connecting the air hose, and positioning the air inlet.
4. Operation
The fishkeeper FK065 filter offers multiple functionalities to enhance your aquarium environment:
4.1. Filtration
The dual biochemical sponge filtration system continuously processes water, removing uneaten food, waste, decaying plants, detritus, and fine floating particulates. This mechanical and biological filtration helps cultivate beneficial bacteria, reducing odors and maintaining a clean, healthy ecosystem.

Image: A visual representation of the dual deep filtration system, showing water flow through two layers of biochemical sponges.
4.2. Wave Making and Circulation
The adjustable direction spout allows you to create natural water currents, promoting water movement and preventing stagnant areas in the tank. This also aids in distributing heat and nutrients evenly.
4.3. Oxygen Supply (Aeration)
By connecting the air hose and positioning its inlet above the water, the filter draws in air and releases fine bubbles into the tank, increasing dissolved oxygen levels crucial for aquatic life. You can adjust the air valve to control the bubble size and aeration intensity.

Image: The filter operating as a wave maker, with an inset showing how to adjust the air valve to control bubble size for oxygen supply.
4.4. Water Pumping
The powerful pump can also be used for water pumping tasks, such as draining water from the tank during water changes, by attaching a suitable hose to the outlet.
5. Maintenance
Regular maintenance is crucial for the optimal performance and longevity of your filter. It is recommended to clean the filter sponges every 10 days.
5.1. Cleaning the Filter Sponges
- Unplug the Filter: Always disconnect the filter from the power supply before handling.
- Remove from Tank: Carefully remove the filter unit from the aquarium.
- Disassemble: Gently squeeze the smooth surfaces of the filter sections to separate them. The filter is designed for easy disassembly. Avoid squeezing the side water intake areas, as this may make removal difficult.
- Remove Sponges: Take out the biochemical sponges from their compartments.
- Rinse Sponges: Rinse the sponges thoroughly in old aquarium water (from a water change) or dechlorinated tap water. Avoid using untreated tap water as it can kill beneficial bacteria. Squeeze the sponges to remove accumulated debris.
- Reassemble: Place the clean sponges back into their compartments and reassemble the filter sections by aligning and gently pushing them together until secure.
- Reinstall: Reinstall the filter in the aquarium, ensuring it is fully submerged before plugging it back in.

Image: A visual guide demonstrating the process of cleaning the filter sponges: squeezing to separate, removing the sponge, and rinsing it.

Image: Instructions on how to correctly disassemble the filter by squeezing the smooth surfaces, and a warning against squeezing the side water intake.
6. Troubleshooting
If you encounter issues with your fishkeeper FK065 Aquarium Filter, refer to the following common troubleshooting steps:
| Problem | Possible Cause | Solution |
|---|---|---|
| Filter not running / No water flow |
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| Weak water flow |
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| Excessive noise or vibration |
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| Green water persists |
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7. Specifications
| Feature | Detail |
|---|---|
| Model Number | FK065 |
| Brand | fishkeeper |
| Power Rating | 16W |
| Flow Rate | 265 GPH (Gallons Per Hour) |
| Recommended Tank Size | 40-170 Gallons |
| Dimensions (approx.) | 10.04 x 4.37 x 2.6 inches |
| Item Weight | 1.3 pounds |
| Color | Black with Blue accents |
| Filtration Type | Dual Biochemical Sponge Filtration |
| Compatibility | Freshwater and Saltwater Aquariums |

Image: A detailed diagram illustrating the physical dimensions of the filter unit.
8. Warranty and Support
8.1. Warranty Information
This product comes with a limited 1-year warranty from the date of purchase. The warranty covers manufacturing defects under normal use. It does not cover damage caused by misuse, neglect, improper installation, or unauthorized modifications. Please retain your proof of purchase for warranty claims.
8.2. Customer Support
For technical assistance, troubleshooting not covered in this manual, or warranty inquiries, please contact the seller or manufacturer directly through the platform where the product was purchased. Provide your model number (FK065) and purchase details for faster service.
