Fluval 306 Review: A Canister Filter To Keep Your Tank Spotless

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A quality filter is a must-have item for your aquarium setup. A filter will improve water quality and reduce the need for cleaning your tank. The Fluval 306 is a favorite among hobbyists thanks to its sturdy design and powerful pump. Our Fluval 306 review will walk you through the features of this canister filter and help you decide if this filter is the right product for your tank.

What Is The Fluval 306?

The Fluval 306 is a performing canister filter from aquatic equipment manufacturer Fluval. It’s a sealed system that requires very little maintenance. Another advantage of the canister design is that the filter is easy to set up.

A canister filter pumps water out of the tank. The water goes through filter media as it circulates through the filter. The filter then pumps clean water back into the container. Canister filters are ideal for large tanks that need continuous filtering.

The Fluval 306 is an exterior filter. You will need to place this filter on the side of your tank or set it up under your tank. This design is more discreet, and you can easily hide the filter in a cabinet.

Fluval has been around since the 1970s. This manufacturer offers a wide range of quality products, including a line of filters. We recommend Fluval products for your tank since there is a team of dedicated experts who genuinely care about developing the best aquatic products possible behind this brand.

The Fluval 306 is part of a larger line of canister filters. The 306 model is a medium-sized filter compared to the other products of the line.

You can use this canister filter in a tank with a capacity of up to 70 gallons, but Fluval recommends that you use this filter in a container that doesn't exceed 30 gallons. However, it seems reasonable to use this filter in a tank with a capacity greater than 30 gallons as long as you don't stock your fish tank too heavily. You can use the Fluval 306 in a freshwater or saltwater tank.

How Does The Fluval 306 Filter Work?

The filter features two valves at the top. The pump sucks water in through the inlet valve. The water circulates to the bottom of the filter before going back up. As the pump sucks the water back up, it goes through different layers of filter media.

The filter stores filter media in three separate baskets. The upright canister design allows you to use more filter media compared to other models.

You will find the pump motor in the cover of the filter. The filter features secure lock clamps to keep the filter closed. You can easily open the lid and remove the different baskets whenever you need to replace filter media. There are some built-in dampeners to reduce the noise of the motor.


​Image Source: www.ebay.com.au

The filter comes with nuts and rim connectors. You can use these components to secure the input and output lines that will run to the tank. The nuts and rim connectors are quality products that will prevent leaks.

We like the casing of the filter. The sturdy plastic casing is water-resistant and will protect the interior of the filter.

The filter comes with ribbed plastic hoses. The diameter of the hoses is ½.” You can easily connect another type of hose to the filter if you want to create a customized setup.

The intake design prevents clogs from forming in the filter. The valves are another standout feature. The quality of the valves makes the Fluval 306 a durable option.

There is a priming button on the filter. This feature will help you get started with this product. You can push this button to get the filter to start pumping water automatically without having to create a siphon manually. Priming can be noisy, but it's a process that shouldn't last more than a few minutes.

Fluval offers a three-year warranty on this product.

A Quick Guide To Filter Media

The Fluval 306 comes with three baskets you can fill with filter media. This design allows you to create a customized three-stage filtering system for your fish tank.

The first filtering stage uses mechanical media. The filter comes with foam pads that prevent clogs by catching large debris.

The middle basket contains biological filter media. The purpose of this stage is typically to eliminate ammonia. You can use carbon, polyester, bio rings, peat granules, or a phosphate filter. This type of media allows beneficial bacteria to thrive, and some of these items double as an additional mechanical filter.

The last filtering stage uses chemical media to remove toxins. It's essential to place the chemical media last since it can be harmful to the bacteria that live in the biological filter media. 

Fluval offers plenty of add-ons for this filter, but you can shop for filter media from any other manufacturer. You can easily design a filtering system adapted to the size and population of your fish tank with these three filter baskets.

What Are the Specs of the Fluval 306 Filter?

The filtration volume of the filter is just under seven liters or roughly above 236 fluid ounces. You can use significantly more filter media than with a round filter or another design.

The 303 GPH flow rate is another interesting spec. This fast flow rate allows you to keep your fish tank spotless, even if you have a lot of fish or stock it with species that require continuous filtering.

Here is a quick summary of the main specs you should know about:

​Product name

​Fluval 306

​​Recommended for

​​Tanks up to 70 gallons

​​Freshwater or seawater


​​Number of filtration stages



​​External canister filter

​​Flow rate

​​303 GPH, or 110L/H

​​Filtration volume

​​236 fl oz, or 6.94L






​​Three-year warranty

​​What’s included?

Valve assembly
Rim connectors
Rubber connectors
Some sellers include filtration media

Fluval 306 A212 Canister Filter w/Bio-Foam, Carbon & Polishing Pads
  • Value pack includes the following media: Bio-Foam Filter Media, Carbon Nylon Bags, Water Polishing Pads
  • Improved motor hydraulic performance that reduces maintenance frequency, increases flow rates and head pressure
  • Enhanced water filtration performance for cleaner, healthier water
  • Better biological filtration, with the addition of Bio-Foam media
  • Sound-dampening impeller design for 8 to 15% quieter operation

How Does the Fluval 306 Compare to Other Filters?

There are a few other products to consider if you need a filter for your aquarium.

Penn Plax Cascade 1000 Canister Filter

Penn Plax Cascade CCF3UL Canister Filter For Large Aquariums and Fish Tanks – Up To 100 Gallons, Filters 265 GPH,Blue
  • CASCADE CANISTER FILTER FOR FRESHWATER OR MARINE ENVIRONMENTS: the Cascade 1000 (CCF3UL) has 3 media baskets, works at 265 GPH, and is recommended for Aquariums up to 100 gallons. It measures 11.5 x 17 x 10 inches.
  • STATE OF THE ART FEATURES OF THE CASCADE 1000: ♦ flow valves that rotate 360 degrees for easy maneuvering in even the tightest aquarium cabinets ♦ large capacity media baskets allow aquarists to customize to their media needs ♦ push button primer allows for a quick and easy prime of the filter ♦ includes a spray bar, tubing, directional spout for customization, and filter medium.
  • USE ANY COMBINATION OF MEDIA: floss pad for removing particulate matter and a course sponge that provides abundant surface for promoting bacterial growth (to remove ammonia and nitrites) included free with purchase
  • SEE BELOW FOR DIAGRAM, THE CASCADE 1000 INCLUDES: ♦ Flow rate control cut-off valves ♦ two independent directional 360 degree rotating valve taps ♦ swimming pool – style hose clamps ♦ quick, easy, push button self-primer ♦ extra-large capacity stackable filter medium containers with lift-up handles ♦ floss pad and coarse sponge included, free with each canister filter ♦ easy lift alignment clamps that release vacuum suction ♦ sturdy tip-proof base
  • FILTER MEDIA OPTIONS BY CASCADE AVAILABLE ON AMAZON, SOLD SEPARATELY: see below for details, sold separately is media such as: bio-floss, bio-sponge, bio-rings, filt-a-pack pro-z, and filt-a-pack pro-carb-z.

The Penn Plax Cascade 1000 features an easy primer mode similar to the one you will find on the Fluval 306. There is a valve that automatically adjusts to the water flow.

The 110V motor is less powerful than the Fluval 306. This pump motor is an advantage if you are looking for a canister filter that uses less power. The downside of this 110V motor is the reduced flow compared to the Fluval 306.

You can use the Cascade 1000 filter for a tank with a capacity of up to 100 gallons. The flow is 265 GPH, which is lower than the 303 GPH flow of the Fluval 306. Unless you keep your tank heavily stocked, the reduced flow shouldn’t be an issue.

The canister design is very similar to the Fluval 306. The water goes in and out of the filter through the valves you will find on the cover. You can easily open the filter to replace filter media. The water goes to the bottom of the filter before going through the three filtering baskets. 

The valves are an exciting feature since they are different from the ones you will find on the Fluval 306. The valves automatically adjust to the flow of water and can rotate. The valves of the Fluval 306 are less flexible, which can limit you when you set up the filter.

You can place the Cascade 1000 anywhere around your tank and easily install the water lines regardless of the angle thanks to the rotating valves.

The filter comes with tubing, spouts, foam filter media, and a spray bar. The dimensions are 11.5x17x10,” which makes the filter bulkier than the Fluval 306.

​Product name:

Penn Plax Cascade 1000


​three-year warranty

​Aquatop CF Series Canister Filter

The Aquatop CF Series canister filter is similar to the Fluval 306 filter in terms of price, but it comes with some features that are missing from the Fluval 306. You need to ask yourself whether or not you need these additional features.

The Aquatop canister filter uses five stages of filtration. It has a flow of 525 GPH that is superior to the performance of the Fluval filter.

One of the additional features is a 9-Watt UV sterilizer light. The purpose of this filtration stage is to eliminate bacteria and some algae spores with a UV light.

The Aquatop CF Series canister filter stands out thanks to its quiet operation. It’s slightly bulkier than the Fluval 306 with dimensions of 18x12x11.”

The design is very similar, but you will notice that the base is larger. This base makes it easy to have the filter stand upright next to your fish tank.

You will find the intake and output valves on the cover of the filter. The first filtration stage is for UV light. The water will then go through four filtration baskets.

The filter comes with carbon pads and ceramic rings or balls. Aquatop offers many different filter media, including foam pads and additional biological and chemical media.

You can use this filter with a tank that has a capacity of up to 125 gallons. The filter comes with valves, hosing, clamps, and a spray bar. It features a 120V motor pump so energy use should be very similar to the Fluval 306.

Product name:

Aquatop CF Series Canister Filter


three-year warranty

We looked at the different features and specs of the filter to create this Fluval 306 review. The canister filter stands out thanks to its sturdy design, flow rate, and performing 120V pump motor. The reviews for the filter are excellent, and we highly recommend it because it's obviously a quality investment of your aquarium setup.

The main downside of the product is the price. It’s possible to find canister filters with similar specs in a lower price range. However, quality might be slightly lower than what you can expect from the Fluval 306.

Pros And Cons Of The Fluval 306 Canister Filter

We looked at the different features and specs of the filter to create this Fluval 306 review. The canister filter stands out thanks to its sturdy design, flow rate, and performing 120V pump motor. The reviews for the filter are excellent, and we highly recommend it because it's obviously a quality investment of your aquarium setup.

The main downside of the product is the price. It’s possible to find canister filters with similar specs in a lower price range. However, quality might be slightly lower than what you can expect from the Fluval 306.


  • ​Easily create a customized filtering system
  • ​High-quality product
  • ​Flow rate
  • ​Suitable for large tanks
  • ​Makes a noticeable difference in terms of water quality
  • ​Comes with everything you need


  • ​Set up can be complicated for novices
  • ​120V motor uses more energy

Verdict And Rating

After researching the product to write this Fluval 306 review, we think the filter deserves a rating of four out of five stars. The filter stands out thanks to its flow rate and sturdy build.

However, other products deliver a better flow rate or have more filtering stage in a similar price range. It’s possible to find canister filters that are more affordable and come with more accessories. We recommend the Fluval 306 if you are looking for a quality long-term investment, but we think there are other options to consider if you are shopping on a budget.


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