Fluval FX6 Canister Filter by Hagen Reviewed: Is it as Good as They Say?

The Fluval FX6 from Hagen claims to offer a simple, worry-free solution for high-performance filtering of tanks up to 400 gallons in volume.

Is the Fluval FX6 the best water filtration system for your aquarium? Our independent review will take a closer look at this canister filter to highlight where it outperforms the competition and where it falls short.

Fluval FX6

Fluval Canister Filter, FX6 Filter (400 Gal)
Fluval Canister Filter, FX6 Filter (400 Gal)

    Last update on 2020-08-08 / Affiliate links / Images from Amazon Product Advertising API

    Overview of the Fluval FX6: High Performance Canister Filter

    The Fluval FX6 is one of the most popular canister filters among aquarists thanks to its huge volume rating and flexibility.

    The filtration system is rated for tanks up to 400 gallons, or 1,500 liters, in size, which alone is enough to pique the interests of many hobbyists. Better yet, the extendable intake tube allows the filter to be adjusted to fit most tank shapes and sizes.

    What really sets this canister filter apart, though, is how easy it makes it to achieve high-performance filtration. The pump is self-priming, so all you need to do to start filtering is to plug it in.

    Every 12 hours, the pump evacuates any air that has become trapped in the system so a highly efficient vacuum is always maintained.

    The Fluval FX6 uses a combination of mechanical, biological, and chemical filtration to keep your aquarium clean.

    While the canister comes pre-loaded with a set of filter media that is suitable for most basic aquariums, all of the filter media can be interchanged to customize the canister for your desired water conditions.


    • Aquarium Capacity: 400 gallons (1,500 liters)
    • Filter Circulation: 563 gallons per hour (2,130 liters per hour)
    • Pump Output: 926 gallons per hour (3,500 liters per hour)
    • Wattage: 43 watts
    • Media Baskets: 3
    • Mechanical Area (Foam): 325.5 square inches
    • Biological Volume: 1.5 gallons (5.9 liters)
    • Filtration Volume: 5.28 gallons (20 liters)
    • Head Height: 10.8 feet (3.3 meters)
    • Warranty: 3 years

    What’s in the Box?

    • Fluval FX6 canister filter
    • Pump unit and power cord
    • Intake stem and output nozzle
    • Purge valve hosing
    • Suction cups and rubber feet
    • Rim connectors, clips, and lid fasteners
    • Utility valve and drain cap
    • Media baskets (3)
    • Bio-foam inserts (2)
    • Carbon filter pad
    • Media packs (2)
    Fluval Canister Filter, FX6 Filter (400 Gal)
    Fluval Canister Filter, FX6 Filter (400 Gal)

      Last update on 2020-08-08 / Affiliate links / Images from Amazon Product Advertising API

      Fluval FX6’s Key Features and Benefits

      Here’s what makes the FX6 stand out from the rest:

      High Capacity

      The Fluval FX6 stands out among aquarium filtration systems for its massive 400-gallon capacity rating. The filter may not have a high enough circulation rate to truly handle 400-gallon tanks, since it would circulate the tank only once every 45 minutes.

      However, the filter’s high-performance pump, which automatically clears air bubbles to maintain a vacuum, gives it a boost in filtration efficiency over other filter systems.

      Despite the high capacity of the filtration system, the canister itself is surprisingly small. It is just 21 inches tall – short enough to fit neatly underneath most aquarium cabinets.

      AquaStop Valves

      When it comes time for maintenance, it’s hard not to appreciate that the Fluval FX6 comes with a pair of AquaStop valves.

      These valves can be turned 90 degrees to stop the flow of water through the intake and outflow tubing, which allows you to purge the filter and disconnect the tubing with ease.

      In the end, this can save a significant amount of time and cleanup when performing routine maintenance on the filter.

      Click-fit Connectors


      The click-fit assembly used to piece the Fluval FX6’s components together is another welcome design feature of this system.

      The intake and output assemblies simply need to be pushed down onto the filter housing until you hear a click – when you do, you know that you’ve achieved a watertight and airtight fit for efficient circulation.

      Lift-Out Stack Media Baskets

      The stack of three high-capacity media baskets is one of the most important components of the Fluval FX6.

      These media baskets can be quickly removed from the filter canister with a simple T-handle release, and then the baskets can be separated to access the filter media in each one. Overall, this system makes it extremely simple and fast to change out and maintain the filter media.

      Better yet, using three media baskets in a stack allows you to customize both the type of filter media that the Fluval FX6 uses and the order in which tank water encounters these media. Each basket is lined with foam to prevent water from leaking past the filtration media.

      Smart Pump Technology

      The pump within the Fluval FX6 incorporates an electronic controller that continuously monitors its impeller speed and force output.

      Thanks to this monitoring, the pump is able to detect when there is air that has built up in the system and can automatically pause once every 12 hours to allow trapped air to escape.

      Thanks to this Smart Pump technology, the filtration system maintains maximum efficiency at all times.

      Purge Valve

      The Fluval FX6 has a purge valve at the base of the canister, which can be opened after the AquaStop valves on the intake and output assemblies are closed. This allows you to remove any water from the filtration system before moving it for maintenance.

      Clog Proof Intake Strainer

      The intake strainer is designed to eliminate clogs, a common problem on other aquarium filtration systems. The strainer is covered by a fine, beveled mesh screen that prevents solids from building up and inhibiting the flow of water into the canister.

      Multi-Directional Nozzles

      Hagen recognized that the current produced by a filtration system is an important part of keeping an aquarium clean.

      The adjustable output nozzle on the Fluval FX6 shoots filtered water in multiple directions, which helps break down suspended waste by agitating the water.

      Even better, the multi-directional output currents help keep this broken down waste in suspension so that it can be captured by the filtration system and doesn’t build up on the bottom surfaces of your aquarium.

      Instant-Start Priming System

      When you first plug in the Fluval FX6, it will fill the canister with water and then begin pumping. The pump will pause for two minutes to evacuate air from the system, then start filtering your tank.

      This means that you never have to worry about manual siphoning again – simply plug in the filter and it will begin cleaning your tank’s water.

      Locking Clamps

      The Fluval FX6 comes with a set of locking clamps that make it easy to ensure that connected tubing won’t break apart under pressure. The clamps tighten down easily, then lock in place so they won’t loosen when you’re away from the tank.

      Water Change Feature

      A utility valve at the bottom of the canister is designed specifically to make changing your tank’s water simple. The valve can be used to drain water from the tank as it flows through the filtration system as well as to feed fresh water back into the tank through the canister.

      Monthly Indicator Dials

      The Fluval FX6 also has a set of dials on the canister that serve to remind you of when it’s time to change the tank. While some users might find it helpful to have this information right on the filter, the same reminder could also be achieved with a calendar or a sticky note.

      Adjustable Water Flow

      The water flow through the Fluval FX6 can be adjusted with the AquaStop valves on the intake and output tubing.

      While turning these valves 90 degrees will fully stop the flow of water, turning them to a lesser angle will adjust the flow rate between the maximum of 563 gallons per hour and zero.

      This allows you to precisely control your filter’s circulation, which is especially important if you are using the Fluval FX6 for a tank smaller than 400 gallons.

      Adjustable Intake Stem

      The intake stem on the Fluval FX6 is highly adjustable so that the filter can be used with the widest possible variety of tanks. Simply extend the stem until it reaches down into the water level of your tank – just keep in mind that the Fluval FX6 has a maximum head height of 10.8 feet.

      Quiet Operation

      Given its large pump capacity and power, the Fluval FX6 is impressively quiet. The filter does produce a low hum, but chances are you won’t notice the noise at all unless you get close to the aquarium.

      Better yet, the filter doesn’t produce the annoying vibrations that many other powerful filtration pumps do.

      Fluval Canister Filter, FX6 Filter (400 Gal)
      Fluval Canister Filter, FX6 Filter (400 Gal)

        Last update on 2020-08-08 / Affiliate links / Images from Amazon Product Advertising API

        How to Setup a Fluval FX6 Canister Filter

        Setting up the Fluval FX6 requires assembling your desired media and cutting the tubing to fit your aquarium:

        1. Place the canister filter directly underneath your aquarium.

        2. Connect the intake and output assemblies using the click-fit connectors. You can also lock down these connectors with the included locking clamps.

        3. Lay out the intake and output hosing so that they reach from the canister into your aquarium. Cut the intake tubing so that it extends about six inches below the top of your tank and adjust the height of the intake stem so that it extends at least one inch below the surface of the water.

        4. Cut the output tubing so that it extends about one inch below the water level of your aquarium. Use a locking clamp to connect the multi-directional output nozzle to the end of the tubing.

        5. Remove the media baskets from the canister using the red T-handle release system.

        6. Fill the media baskets with either the included filter media or with your own choice of filter media, as desired. Be sure to leave at least half an inch of space at the top of each basket so they fit together without allowing leaks.

        7. Re-stack the filter baskets and place them inside the canister. Lock down the lid of the filter canister by hand-tightening the eight lid fasteners.

        How to Clean a Fluval FX6 Canister Filter

        Cleaning the Fluval FX6 is relatively simple thanks to the AquaStop and purge valves, which together allow you to remove all of the water from the canister.

        Even better, the simple removable filter basket system and click-fit connectors on the intake and output assemblies make accessing the various components of the filtration system easy.

        1. Close the AquaStop valves on the intake and output tubing and unplug the filtration system from your electrical outlet.

        2. Place a bucket underneath the purge valve, then open the purge valve to release any water still in the canister. Then move the canister to a more suitable area for performing maintenance.

        3. Change out the filter media by opening the top of the canister and releasing the media baskets, just as you did when installing media. When changing out the media, be sure to leave at least one-half inch of space at the top of each basket so the baskets fit together completely.

        4. Access the pump to maintain it and clean the impeller. Turn the canister over and unscrew the screws that hold the pump unit in place. Then remove the impeller assembly and clean it by washing with fresh water.

        5. Put the canister back together first by replacing the impeller assembly. Align the two arrows on the assembly and then push it firmly back into place in the housing.

        6. Replace the media baskets, ensuring that they are stacked without excess space between them. Fasten the lid on the canister, reconnect the hoses, and open the AquaStop valves.

        7. When ready, plug in the filter to your electrical outlet, allow the self-priming sequence a few minutes to complete, and then check for leaks after filtration has restarted.

        Maintenance Schedule Table

        [wpsm_comparison_table id=”28″]

        Fluval FX6 Pros & Cons

        Here’s a rundown of my pros & cons:

        FX6 Pros

        • Filtration for tanks up to 400 gallons in volume
        • Includes three customizable filtration media baskets
        • AquaStop and purge valves make maintenance relatively easy
        • Automatic priming system
        • Smart Pump technology removes air bubbles for maximum efficiency
        • Adjustable multi-directional output nozzle
        • Three-year warranty

        FX6 Cons

        • Foam inserts in filter baskets require relatively frequent replacement
        • Canister is somewhat bulky
        • Expensive (depending on budget)

        Verdict: Who is the Fluval FX6 Ideal For?

        The Fluval FX6 is on the expensive side for an aquarium filter, but it’s hard to beat the impeccable design features of this filtration system.

        For aquarists with large tanks, the quiet operation and large pump and media capacities of the Fluval FX6 can be well worth the money.

        Plus, you won’t find a filtration system that makes maintenance easier than the Fluval FX6, which allows you to drain water from the canister before moving it and even lets you add and remove water from the tank directly through the canister.

        Fluval Canister Filter, FX6 Filter (400 Gal)
        Fluval Canister Filter, FX6 Filter (400 Gal)

          Last update on 2020-08-08 / Affiliate links / Images from Amazon Product Advertising API

          Alternatives to the FX6

          Here are some alternative canister filters for you to take a look at:

          Fluval Canister Filter, FX4 Filter (250 Gal)
          Fluval Canister Filter, FX4 Filter (250 Gal)
            Hydor Professional External Canister Filter – Aquarium External Filter – Telescopic Intake Tubes, Easy Priming – EcoSystem in a Box – Biological, Mechanical, Chemical Filtration – 190 to 345 gph
            Hydor Professional External Canister Filter – Aquarium External Filter – Telescopic Intake Tubes, Easy Priming – EcoSystem in a Box – Biological, Mechanical, Chemical Filtration – 190 to 345 gph
              Ehm Fltr 2217 Classic Wm 264g
              Ehm Fltr 2217 Classic Wm 264g

                Last update on 2020-08-08 / Affiliate links / Images from Amazon Product Advertising API

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                Fluval fx6 cainsiter from Hagen reviewed: In this guide, we'll break down the product and go through the features so you can learn why it's so highly rated #modestfish #aquarium #filter
                Read on this article, we’ll share some tips, how to cycle your tank with the nitrogen cycle process that can helps avoid your fish’s waste releases ammonia into the water. #modestfish #aquarium #cleaning

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