Don’t be fooled, the Fluval FX6 canister filter is compact but not many filters on the market can boast besting it. For starters it can be used with any freshwater or saltwater aquarium. 

The FX6 is a brilliant and powerful external canister filter with some brilliant features that put it up there with the best. It has a large capacity; it is suitable for fish tanks of up to 400 gallons. With multiple filter media baskets you also get up to 6 filtration stages. 

Is the Fluval FX6 Canister Filter right for your tank? This review will hopefully clear things up for you. But if you want to skip the read, the short answer is yes!

Fluval Fx6 Aquarium High Performance Canister Filter
  • Multi-stage Filter that produces healthy aquarium water, freshwater or marine aquariums
  • Features Smart Pump Technology for optimum filter performance, efficiency and management
  • Self-starting filter-just add water and plug in. Head height (maximum): 3.3 m (10.8 feet)
  • For aquariums up to 400 gallons

Fluval FX6 Aquarium Canister Filter Review

Fluval FX6 Aquarium Canister Filter Review

High capacity canister filter

Delivering more than expected, the Fluval FX6 canister has earned its reputation as the ultimate filter. The large capacity and powerful pump delivers superior performance and capacity. This means the canister can filter 925 gallons of water per hour, and can be used to filter large 400 gallon aquariums. Such capabilities means keeping those aquariums clean and filtered just got simpler and easier. You’ll have to look elsewhere if you have a small fish tank!

Despite such high capacity ability, the FX6 is only 21 inches in height, which means that it should fit with no problems under most large aquariums.

Stacked filter media baskets 

A unique selling point of the FX6 canister filter is the multiple stacked media baskets. This stacked design prevents water bypass as you can find in more conventional filter designs. Foam media between the stacks further prevents water bypass. It also enables the canister to be more compact than it should be.

The filter baskets hold a total of 1.5 gallons of media. With the filter you get all biological, mechanical, and chemical media that you need. It is also very easy to purchase any additional media that you need. When it comes time to change or clean the filter media the basket design means that it is very easy to do so.

You can also use the basket design to customize how the media is layered. This means you have full control over in what order the aquarium water comes into contact with the media.

Fluval FX6 High Performance Aquarium Filter, Canister Filter for Aquariums up to 400 Gal., A219

Reduced noise of operation

The FX6 is not just a one trick pony; it works quietly as well as having a high capacity canister. So much so that you need to get pretty close to realize it’s even on!! It gains this low noise level by utilizing unidirectional impellers which have less mechanical joints, thereby have less noise.

Not only is it quiet, but makes less vibrations than other canisters. It features rubber feet, which help to reduce the vibration levels. A common problem with external canister filters is vibration. Not only is this an annoying sound, it isn’t great for your fish either.

However the Fluval FX6 canister filter has been engineered to minimize sound and vibrations, which is both best for your aquarium and your peace and quiet!

Multi-directional output

The manufacturer included a twin output nozzle to help with distributing the filtered water to all corners of the aquariums. The nozzles can be adjusted to various modes of output, depending on the aquarium filtration needs.

This is a great feature as it helps to disperse the newly filtered water throughout the tank. In larger tanks especially this is a good thing, as you don’t want dead spots to appear in your tank.

Aquarium powerheads or wavemakers can help with this too, but the dual output nozzles help to reduce this need.

Smart pump technology

Any good system will be able to monitor its own condition and the FX6 canister filter is no exception. The manufacturer has installed an electronic circuit board which composes a continuous monitoring system.

This constantly monitors performance​ and ensures every part stays in working condition and output is maximized; the impeller speed and pump output are constantly checked. Not only does this work to improve performance but it also increases the energy efficiency. 

The smart pump technology also enables the pump to stop once every 12 hours to expel any trapped air in the system. This helps to maintain maximum filtration efficiency.

Aqua stop valves

This filter comes with aqua stop valves which makes performing maintenance to the aquarium or canister filter very simple and easy. By turning the valve lever the valves enable you to stop water flow in the canister.

The hose can then be separated and maintenance can then be undertaken without having to worry about water spillage and damage or destruction of filter components. Simply the valve lever back into the starting position to get the water flowing away once maintenance has been completed.

Self-priming start system

Most aquarium owners know the taste of their own aquarium water from trying to siphon the water into the canister before the the filtration can start. This method is left obsolete by the FX6 canister filter, so you’ll no longer run the risk of getting a mouthful of fish water.

The Fluval FX6 model makes life so much easier by offering a self priming system. This system is programmed to automatically flood the system with water before filtration begins. The filter will pause for two minutes to expel any air from the system before filtration self-starts.

Utility valve drain

This is yet another brilliant feature on the Fluval FX6 aquarium canister filter.  The utility valve drain acts as an easy way to undertake water changes. It is possible to drain the tank as the water runs through the filter. You can then easy refill the tank by connecting to the utility valve again.

It also acts as a great way to power the FX Gravel Vac for superior substrate cleaning. You simply attached the gravel vac to the utility valve drain and the filter then powers the vacuum to remove dirt and debris from the substrate. This dirt is caught in fine mesh bags. This prevents the messy job that is usually the norm in aquarium vacuum cleaners.

Clog proof intake strainer

The intake valve of the filter is fitted with a clog proof intake strainer. A common issue of canister filters, and indeed hang on back filters as well, is that the intake valve can get clogged with algae or debris.

With the clog proof intake strainer though, this common issue is prevented. The strainer is equipped with a very fine, beveled mesh screen which works to prevent solids from building up and inhibiting the flow of water into the canister filter.


While it is a tad pricy, if you’re willing to spend the money it will be the best and most worthwhile money you’ve spent on an aquarium filter. The FX6 is the most user friendly filter and always delivers on its promises. Being able to filter 400 gallons of multiple aquariums makes the FX6 unique amongst its peers. Buy it now to see all the brilliant attributes it can offer you and your aquarium.

Similar product reviews:

Fluval FX6 Aqarium Canister Filter








Flow Rate


Filtration Media



  • Large capacity and powerful flow rate
  • Clog proof intake strainer
  • Easily maintained by using the aqua valves
  • Water change feature
  • Self priming


  • Fairly expensive

About the author

Authority Aquarium Staff

Authority Aquarium Staff writers are experts and aquarium enthusiasts, our in-house marine biologist fact checks all our content and reviews to bring you the best advice for your aquarium health.

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