Fluval external filters are among the most reliable and widely used canister filters in the aquarium hobby. Known for their power, quiet operation, and ease of maintenance, Fluval filters are a top choice for freshwater and marine aquariums alike.
Whether you’re setting up a Fluval filter for the first time or looking to troubleshoot an issue, this guide covers everything you need to know.
What is a Fluval External Filter?
A Fluval external filter is a canister-style filtration system that sits outside the aquarium. It draws water from the tank via an intake tube, processes it through multiple filtration stages inside the canister, and returns clean water via an outflow pipe. Fluval filters are known for their multi-stage filtration, which includes mechanical, chemical, and biological media to ensure crystal-clear, healthy water.
Popular models include:
• Fluval 107, 207, 307, 407 (for tanks up to 500L)
• Fluval FX4 and FX6 (high-performance filters for large aquariums)
How to Set Up a Fluval External Filter
Step 1: Assemble and inspect the filter
Unbox the filter, check that all parts are present, and assemble according to the instruction manual. Place the media in the correct order, typically mechanical media on top, followed by chemical and biological media.
Step 2: Position the canister filter
Place the filter below the waterline of the aquarium (usually inside a cabinet). Attach the intake and output hoses securely.
Step 3: Prime the filter
Fluval filters include a built-in priming system. Press the priming handle several times to start siphoning water into the canister.
Step 4: Plug in and check flow
Once the canister is full, plug in the unit. You should hear the motor hum and water begin to circulate. Adjust flow using the intake/output valves if needed.
How Often Should You Clean a Fluval Filter?
Routine maintenance is essential to keep your Fluval filter working efficiently. As a general guide:
• Mechanical media (foam pads): Rinse every 2–4 weeks
• Chemical media (carbon, ammonia remover): Replace every 4–6 weeks
• Biological media (BioMax): Rinse gently in tank water every 1–2 months (do not replace unless damaged)
Always turn off and unplug the filter before performing maintenance. Clean the impeller and tubing every few months to prevent blockages and noise.
Troubleshooting Common Fluval Filter Problems
No flow or weak flow:
Check for airlocks, clogged intake hoses, or dirty media. Re-prime the filter and ensure the hoses are not kinked.
Noise or vibration:
Inspect the impeller and clean out any debris. Ensure the canister lid is sealed properly.
Leaking:
Check O-rings and hose connectors. Replace worn seals and lubricate with Fluval-approved silicone grease.
Not priming properly:
Fill the intake hose with water manually, ensure the priming lever is functioning, and check all valves are open.
What Media Should I Use in My Fluval Filter?
Fluval canisters are versatile and allow for custom media setups. For most freshwater aquariums, use:
• Top basket: Foam pads (mechanical filtration)
• Middle basket: Carbon or ammonia remover (chemical filtration)
• Bottom basket: BioMax or ceramic rings (biological filtration)
For planted tanks, consider adding phosphate removers or fine polish pads. For marine tanks, you might use additional chemical media like GFO or activated carbon.
Where Can I Buy Fluval Filter Parts and Accessories?
You can find a full range of Fluval spare parts, media refills, and hosing kits at Charterhouse Aquatics. We stock all major Fluval models, including the FX series, along with priming caps, impellers, pre-filters, and upgrade kits.
Shop Fluval Filters & Accessories
Which Fluval Filter is Right for My Aquarium?
• Fluval 107 – Up to 130L (ideal for nano tanks and smaller setups)
• Fluval 207 – Up to 220L (suitable for community tanks)
• Fluval 307 – Up to 330L (great for planted tanks)
• Fluval 407 – Up to 500L (perfect for larger freshwater aquariums)
• Fluval FX4 / FX6 – For aquariums up to 1000L+ (best for cichlids, marine tanks, or heavily stocked setups)
Summary
Fluval external filters are a smart, reliable choice for anyone looking to maintain a healthy and clean aquarium environment. Whether you’re running a nano tank or a 1000-litre monster setup, there’s a Fluval filter designed to handle your system with ease. With proper setup and regular maintenance, your Fluval filter will deliver years of quiet, powerful performance.
