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Fluval FX6 Fish Tank Filter Review

The long awaited Fluval FX6 from Hagen has finally arrived, but is this a match and better than the long standing FX5, how has it improved and is it worth upgrading from the FX5 to the FX6? These are all questions I hope we will cover in this independent review of Fluvals FX6 fish tank canister filter.


It is best to start with how epic the predecessor to the FX6 actually is, the Fluval FX5 filter, in my opinion, was seen as the ultimate in canister filter for any aquarium over around 300 litres. That said, it was capable of filtering much larger aquariums due to the huge rating of 1500 litres.

The Fluval FX6 external canister filter has some stats which are worth shouting about:

  • Rated for aquariums up to 1500 litres (400 US Gallons)
  • Pump output of 3500 litres (925 US Gallons) per hour
  • Filter circulation of 2130 litres (563 US Gallons) per hour
  • Total filtration volume of 20 litres (5.28 US Gallons)
  • Filtration media volume of 5.9 litres (1.56 US Gallons)
  • Mechanical filtration area (foam) of 325.5 in2  / 2100 cm2
  • Maximum head height of 10.8ft / 3.3 m


Filtration is handled by 3 removable stacks of filter media baskets which are precision-engineered to eliminate water by-pass, making filtration more efficient. These baskets are surrounded by a total of 6 removable foams for effective mechanical pre-filtering. Routine maintenance is made simple by a T-bar system which allows all foams to be removed and then separated.

Not only does the 3 different baskets allow for easy separation of filter media in your Fluval FX6 filter, the great thing about the FX6 is that it comes complete with all filter media so there is no need to buy any extra media unless you wish to use a different type of media to that provided out of the box.


The box contents of the Fluval FX6 canister filter not only includes the filter media and foams but also includes all necessary pipework and attachments to allow you to simple plug and play. As if this wasn’t enough the Fluval FX6 from Hagen also features their smart pump technology which was found in the FX5 which is an advanced technological feature that continually monitors the pump, constantly measuring impeller speed and force to ensure powerful output and energy efficiency.

It also manages the filter’s self-starting feature and evacuates air that may enter or build up within the filtration system. On a 12-hour cycle, the pump will pause and allow trapped air to escape, ensuring the best filtration efficiency at all times. The FX5 filter ran on a 24 hour cycle so this being reduced to 12 hours now is yet another improvement over the previous model.


There is always cause for concern when you start your Fluval FX6 filter when you notice after a minute it is not working, fear not though, this is meant to happen! With the FX6, there’s never any need for manual siphoning. As soon as you plug the filter in, the canister fills with water from your aquarium. It pumps for 1 minute, pauses for 2 minutes to evacuate air from the system, then immediately begins the filtering process.

The motor itself used on the Fluval FX6 is now more efficient than the Fluval FX5 and as such will consume 10% less electricity whilst delivering better performance, yet another positive improvement. Whilst we are talking about the changes made over the predecessor, the Fluval FX6 features 2 maintenance indicator dials on top of the unit to help you remember the last time you performed a water change (Left dial) and changed the filter media (Right dial) within the unit. Just making your life even easier!


At only 54cm (21″) in height, the Fluval FX6 manages to pack a whole heap of filtration punch in to a unit which will fit under most aquariums.

Shipping with a 3 year manufacturers warranty the Fluval FX6 has an SRP of £299.99 which is a bargain considering all the features and rock solid build quality you can be sure to get with this and any other Fluval product from Hagen.

In summary I would highly recommend the Fluval FX6 external canister filter and if the success of the FX5 is anything to go by then I am sure this will soon become the filter of choice for many aquarists.