Fluval 306 External Filter Review

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Are you in the market for a filter to try and keep your aquarium clean and your fish happy? Well, the Fluval 306 External Filter might be exactly what you’re seeking.

It works for a number of different aquarium sizes, operates in both fresh and salt water, is quiet, and comes with media included.

fluval 306 review

However, unfortunately, not everyone has fallen in love with this filter. Some users have found it’s more expensive than its competitors, that it’s too bulky, and that it’s difficult to clean.

But before you make your final decision on whether this is the ideal choice for you, let’s take a more in-depth look at the Fluval 306 External Filter.

Fluval 306 External Filter: The Details


  • Weight: 15 lbs.
  • Dimensions: 6 x 14.5 x 16.2 inches.
  • Filter Capacity: 70 gallons.
  • Flow Rate: 260 gph.
  • Media Stages: Mechanical, chemical, and biological mediums.
  • Self-Priming or Standard: Instant-prime.
  • Warranty: Three-year warranty.


Multi-Stage Filtration System

The Fluval External 306 Canister Filter comes with a three-stage filtration system that encompasses mechanical, chemical, and biological stages.

The mechanical stage includes a vertical twin foam pre-filter to ensure the water flows as easily as possible.

The chemical and biological stages are in their own individual compartments for quick access and maintenance.

This also means there is always a constant level of nitrifying bacteria, which is very much needed in the aquarium and for the fish.

Instant Prime

The Fluval 306 filter also includes an instant prime feature.

When you have the filter all set up, all that’s needed is to pump the lever at the top of the filter head and that’s it. You’ve primed your filter.

Talk about easy!

fluval 306 review


The set-up is also relatively easy. If you’re familiar with installing a canister filter, you know the drill. If not, you may want to look for videos online and pay special attention to the instructions included.

You should put all the pieces into place, make sure all the media pieces are where they’re supposed to be, and then install the filter where you desire it on your aquarium.

You also want to ensure the hoses are cut to the length necessary for your tank, and then connect them to their corresponding heads.

Once the filter is all set up, then you can prime the pump by pushing it a couple of times. Then you’re ready to go!

Sound-Dampening Impeller

The Fluval 306 External Filter also comes with a sound-dampening impeller, which means this filter will be much quieter than others on the market.

You can place your aquarium wherever you desire without worry that it will cause noise or a distraction.

Aqua Stop Valve

Fluval’s patented Aqua-Stop valve makes it all the easier to connect and disconnect hoses to and within the 306 External Filter.


  • Four foam pads.
  • 2 x 70 g carbon.
  • 2 x polishing pad.
  • 2 x 120 g BioMax.
  • 2 x bio foam.
  • Ribbed hosing.
  • Two rim connectors.
  • Intake tube.
  • Intake strainer.
  • Output nozzle.
  • Two rubber connectors.
  • Instruction manual.
  • Quick start manual.


The Fluval 306 External Filter also comes with a three-year warranty, which covers anything that goes wrong with your filter due to any defects in “the material or the workmanship” of the product under normal everyday use.

If a part needs to be replaced or repaired, Fluval will do that free of charge. The warranty begins from the day you purchase the filter, so keep ahold of your receipt!

We should note that Fluval doesn’t cover any damages caused by the owner so be sure to handle your new canister filter with care.

Fluval 306 review

The Positives


A number of our testers on the Fluval 306 External Filter noted how quiet it is. It does make some noise while priming, but after you have that all setup, you won’t hear a peep from the device.

One user even stated they had to double check it was working due to just how silent it is. That is what you want from a filter! It can easily blend into your home environment with complication.

No longer will you have to be annoyed by the whirr of your aquarium, or have to avoid conversation in a certain room because of your filter.


This filter is also incredibly versatile. It works for both fresh and saltwater tanks, can work through a lot of water in a little bit of time, has large media baskets, and even includes a hydraulic motor that ensures you won’t have to perform maintenance as often.

Fluval even recently redesigned their impeller cover to boost its durability. They’ve used ceramic in their new design to help withstand against corrosion and breakage.


Users have also noted how powerful this device is. It can filter through 260 gallons of water per hour. That is quite a lot!

The motor and the water filtration performance ensure that the filter catches everything you want it to – and relatively quickly at that.

fluval 306 review

Even with all the media you can put inside this filter, the flow rate is still that high. Your fish will never have to deal with waiting for the filter to clean their water; they’ll just appreciate living in a clean environment.

Large Capacity Media Baskets

Not only can the filter handle up to a 70-gallon aquarium, but the media baskets in the filter are also quite large.

They can hold a wide range of different filtration mediums (biological, chemical, and mechanical), so you can have a customized cleaning solution for your needs.

However your fish prefer to live, you can make it happen with the media baskets.


Users also mentioned how durable the 306 filter is. They described the plastic as firm enough to hold up to everyday use, as well as durable to the touch.

At a full 15 pounds, it is heavier than normal, but not so bulky that it can’t be moved to the sink for easy clean-up.

This includes lift-lock clamps ensure that the motor is locked into place only upping its durability and extending its overall life.

Its strong build along with the included warranty will ensure that you won’t have to worry about your canister filter lasting the years to come.

Users also described it as not feeling wobbly – a common problem in filters – and when you are paying over a hundred dollars, that’s definitely a welcomed perk.

Easy to Use

The inclusion of the AquaStop valves and the lift lock clamps turn maintenance into a dream. No more getting water everywhere!

The motor will stay in place when you need it to. Because you receive three baskets for media, they’re easy to switch out and replace at will; no complicated process needed. You only have to take out one basket instead of one big container that holds all three.

The instant priming (no manual siphoning of water) also doesn’t hurt in the ease-of-use department.

Plus, if you should come across any trouble putting together or using the filter, there are numerous tutorials online, and the filter comes with an instructional DVD.

This makes it less daunting for beginners to own this canister filter, as it won’t be a bumpy ride learning to handle it. What’s best is your fish will love you for providing for them such a clean home!

Customer Service

You can rest assured you’ll be in good hands when choosing the Fluval 306, or when choosing any Fluval product to be exact.

They’re known for having outstanding customer service that’s attentive and always willing to lend a helping hand.

Whether you need to contact customer service for a repair, replacement, or just need a little advice on your new product, they’ll have your back.

The Negatives


Some users thought the filter was just too big for their needs. Make sure you look at the measurements and the weight of the filter before making your purchase.

best canister filter

If you think it’s too big or it’s too much for the aquarium you have, there are a number of other options on the market.

May Surpass Some Budgets

Quite a few users mentioned how expensive this Fluval filter is compared to others of its kind.

Many people don’t like the fact that its price point lands a little under $200 on Amazon, and while this filter does seem to provide many benefits, that may be too much for a sensible budget.

That being said, there are a number of canister filters that are sold at way beyond the price of the Fluval 306 that don’t perform in the same way.

Know that you’ll be getting great quality and durability for the price, making this more of a deal than an issue, though those on a budget may need to work up the nerve.

Clean-Up Issues

Other users didn’t like how delicate they had to be while cleaning the filter. In their experience, you need to be careful when washing the impeller, because if it stops working, the filter will not operate at all.

You must also clean each media compartment separately as they are separate areas in the filter.

Since you’ll be taking apart so many pieces, washing them, and then putting it back together, it may be too much of a hassle, though Fluval has done work to make their filters easy to assemble and disassemble in hopes of better handling.

Here’s a video showing an example on how to set up your Fluval 306 Filter.

 Overall Verdict

After reviewing all the positives and the negatives, we do recommend the Fluval 306 External Filter.

Based on tester experience, it is easy to use, pretty quiet and works for a lot of different aquarium sizes. And while there are some issues with cleaning the filter, the positives far outweigh the negatives in this case.

Overall, you’ll have a powerful filter, that’s sure to make your aquarium happy with the Fluval 306.

Where to Buy the Fluval 306 External Filter

Fluval has definitely made some waves with their line of external canister filters. The Fluval 306 isn’t the only one of its kind turning heads; the whole line has been getting rave reviews from aquarium owners and enthusiasts.

With this company already having a number of successful products under their belt, the Fluval 306 External Filter won’t be hard to find in-store and online.

While it’s always best to check pet and specialty stores, you can kick-start your search with the following online retailers.

But of course, you can also find this filter on Amazon.

Fluval 306 external filter

That’s it for our Fluval 306 review! Tempted to give it a try?

Fluval 306 External Filter Rated
  • Quality of Filtration
  • Build Quality
  • Accessories
  • Ease of Use
  • Value for Money

FCG Verdict

If you’re looking for an external canister filter that’s easy to use, versatile, and powerful, you may have found it with the Fluval 306 External Canister Filter.

With just a few faults to consider with this canister filter, you’ll be backed by a warranty and customer service that has your back should issues arise.

>>> Check current price on Amazon.

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