Fluval FX4 High Performance Canister Filter (up to 1000 L tank with 2650 L/h)

No. of units sold: 30


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FX4 High Performance Canister Filter – Ideal choice for aquariums up to 250 US Gal (1000 L). 5 YEARS WARRANTY. Calculate your tank volume here

FX4 High Performance Canister Filter – Ideal choice for aquariums up to 250 US Gal (1000 L) with a Pump Performance of 2650 L/h (L x W x H – 40 x 40 x 42 cm)


Building off the high-performance FX platform, the all-new FX4 canister filter bridges the gap between the Fluval 407 and the FX6 canister filters, making it an ideal choice for aquariums up to 250 US Gal (1000 L).

  • Multi-stage filter pumps out 700 gallons (2650 L) of water per hour
  • Smart Pump™ – advanced microchip technology continuously monitors and optimizes pump performance
  • Self-starting – just add water, plug in and Smart Pump™ will take over. Trapped air auto-evacuated every 12 hours to ensure maximum efficiency
  • Easy water changes eliminate need to lift heavy buckets. Simply attach hosing to output (Kit sold separately) and Smart Pump™ does the rest
  • Removable, stackable media baskets eliminate water bypass and hold a total of 1 gallon (3.9 L) of media
  • All filter media included – mechanical, chemical and biological
  • Aqua-Stop valves with leak-proof Click-Fit attachment system
  • Valves positioned at convenient 45-degree angle for easy installation and rotation
  • Anti-clog, telescopic strainer ensures continuous water flow
  • Multi-Directional Output nozzles can be fully adjusted to create customized water flows
  • Utility Valve with drain hose for easy maintenance and flushing of canister
  • Rubberized feet help ensure quiet operation
  • Compact 16.5″ tall design – easily fits under most aquariums
  • Made in Italy, Instruction manual.
  • For use in freshwater and saltwater aquariums. Click here for more details.
  • Pump Performance of 2650 L/h, L x W x H – 40 x 40 x 42 cm)
  • 3 YEAR LIMITED WARRANTY (plus a 2-year extended warranty upon registration). For registration please visit:
  • Fluval filter series is guaranteed against defects in material and workmanship under normal aquarium usage and service for 3 years from date of purchase when the complete pump is returned with proof of purchase and postage paid. This warranty does not apply to any filter that has been subject to misuse, negligence or tampering. It does not apply to filters which have been incorrectly assembled or unsuitably maintained or where installation and maintenance instructions have not been followed correctly. It does not apply to wear and tear parts such as the impeller, impeller cover or motor seal. No liability is assumed with respect to loss or damage to livestock or personal property irrespective of the cause thereof. WARRANTY IS ONLY VALID WITH PROOF OF PURCHASE FROM AN AUTHORIZED FLUVAL DEALER. WARRANTY DOES NOT AFFECT YOUR STATUTORY RIGHTS.
  • Package contents:
    1. Ribbed hosing of length 14 feet
    2. Rim connectors, clips and suction cups
    3. Intake stem
    4. Output nozzle
    5. Lid fasteners
    6. Filter canister
    7. Utility valve and hosing
    8. Drain cap
    9. Pump unit (motor) and power cord
    10. Rubber feet
    11. Media baskets
    12. 1/2 media baskets
    13. Filter lid and accessories


Can I connect an inline heater model to my filter?

No. Fluval canister filters use ribbed flexible hosing, which is not ideal for installing such equipment.

Why do I have difficulty restarting my canister filter after cleaning it?

First, check your impeller and impeller shaft as it’s possible either of these are damaged and need to be replaced, or are very dirty and require cleaning. It’s also possible the impeller cover has not been reattached correctly. Finally, verify that the filter has been properly primed: always ensure that the filter output is above the water surface when priming.

I noticed decreased performance and increased maintenance frequency on my canister filter. Am I doing something wrong?

This usually indicates an increased load on your filter due to either the growth of your fish, the recent introduction of additional fish, increased waste production (i.e. leftover food, excrement, etc.), or clogged filter media in need of replacement.

I have a marine tank and noticed bursts of air coming out of my filter output. Should I be concerned?

Air input into your system is most likely coming from the skimmer. Fine air bubbles are gathering in the canister filter and are being ejected in bursts. Consider adding a bubble trap for your skimmer.

I replaced the impeller of my canister filter and noticed a small leak coming from the handle when shutting down. What should I do?

The leak is most likely from the canister O-ring. Before you purchase a replacement, remove and clean it with warm water. Thoroughly wipe the receiving groove in the filter with a soft cloth. Apply Fluval lubricant (#A325) to the o-ring.

How does head height affect filter output performance?

This is a closed recirculation filter system, therefore, head height has no real impact on performance. Length of tubing and filter media are key factors affecting filter output performance. We recommend never exceeding the specified vertical distance in your instruction manual as this will cause the filter to exceed the maximum head pressure value, which could cause the filter to leak and fail.

I change the carbon in my filter every couple of weeks. Is this too often?

No. It’s better (and easier) to prevent odors versus having to remove them once they’ve accumulated. Some fish are messy eaters, or are more prone to producing large amounts of waste, so prevention is key.

Do you have any tips for fixing common filtration issues?

Aquatic expert Tom Sarac discusses the 6 most common filter problems, while providing helpful troubleshooting tips to resolve them.

I found a fish stuck to the intake of my filter. Is the flow too strong?

You don’t need to be concerned about the filter being too powerful for use with healthy fish, many of whom swim in natural habitats with stronger currents. Take note you can adjust the filter output strength to suit your particular fish species.

I just purchased a Fluval canister filter for my well-stocked tank. Is there additional media required (other than what came with the filter)?

Yes, Fluval Total Clear will crystallize the water and rapidly remove organics, providing better overall water quality. Also consider adding a coarse pre-filter media at the bottom of the filter to support improved long-term performance.

What’s the best combination of media if I’m keeping very messy fish?

For aquariums with species that are strong feeders and fairly messy in nature (i.e. digging habits), we recommend using Fluval Fine-Filter pad and chemical media (i.e. carbon) at the bottom level, Fluval Bio-Max in the middle and Fluval Pre-filter rings at the top level.

What motor maintenance should I perform regularly to ensure the longevity of my filter?

Learn how to properly maintain your FX canister filter motor from Fluval’s head aquatic expert.

What general maintenance tips do you have for this filtration series?

Learn valuable tips from our head aquatic expert on how to maintain and take care of your Fluval FX canister filter.

Why is the motor of my canister filter making a low, rumbling noise?

Noise originating from the motor suggests that the impeller assembly needs to be replaced.  As the only moving part in your filter, the impeller does eventually wear and is, therefore, not covered under warranty. Equally important is verifying that the filter has been properly primed (always ensure filter output is above water surface when priming).

How do I know when it’s time to change my filter media?

Aquatic expert Tom Sarac provides guidelines on knowing when to switch out the most common Fluval media for your aquarium filter.

Why is my canister filter emitting bursts of fine air bubbles on my aquarium?

FRESHWATER: It’s important to perform regular filter maintenance (media rinsing and replacement) to prevent media from compacting, which can result in air accumulation. Also make sure to verify the inlet rubber hose connector that attaches to the siphon tube, which does dry out over time and becomes hard and non-flexible, thus requiring periodic replacement.

SALTWATER: This is probably due to your filter taking in the fine air bubbles introduced to the aquarium by protein skimmers. Make sure to use an effective bubble trap at the skimmer output or within the sump to prevent this from happening.

How does water flow through an FX series canister?

The water first moves to the bottom of the canister, and then rises to the top through the foam pads. It then passes back to the bottom of the canister through the media trays in the middle, before finally being returned to the aquarium.

Packaging sizes: FX4 unit (item no. A214)

Select the size below