Fluval 405 vs 406 External Filter Comparison | Aquascape Addiction

Fluval 405 vs 406 External Filter Comparison

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A detailed comparison of the Fluval 405 vs 406 External Filter, differences, pros and cons of each to help you decide which is best for you.

Fluval 405 vs 406 External Filter Comparison

We are here today to talk about 2 popular external filters in a detailed comparison, the Fluval 405 vs 406. Now both are of course decent options but a lot of people often want to know what is the actual difference between the two? And what is better? Let’s get right to it with our overview and comparison of them.

First let’s look at the main difference between the filters then we will cover a very detailed overview of each.

Fluval 405 vs 406 – The Main Differences

You can check the price of the 405 here and the 406 current price here.

There are some key differences between the Fluval 405 and the Fluval 406 External Filters, so let’s take a little time to note what they are.

  1. The 405 can pump out 340 gallons per hour while the 406 can put out over 380 gallons per hour.

  2. The 405 has a special heat protection system to stop the motor from overheating, something which the Fluval 406 does not have.

  3. The Fluval 406 has easy lift clamps, making it easy to attach and remove. While the 405 is not hard to attach, it does not have these easy to use clamps.

  4. The Fluval 406 is much quieter than the Fluval 405.

Fluval 406 External Filter Overview

A great external filter option to go with, the Fluval 405 is tough, reliable, and it can handle a whole lot of mess. If you need a filter that won’t take up any room in the tank, the Fluval 405 is a good option to keep in mind.


The Fluval 405 External Filter has quite a few features that make it one of the better filters around. First off, this is a multi-stage filtration system that includes all three of the major types of filtration, those being mechanical, biological, and chemical. In other words, any waste, debris, bacteria, and unwanted compounds in the water can be easily removed by the Fluval 405. The media baskets are removable, allowing you to customize the filtration process, plus it makes this filter fairly easy to clean as well.

The Fluval 405 can hold up to 40% more water volume than various other canister filters of the same size. Therefore, this model can handle aquariums up to 100 gallons or 400 liters in size. The flow rate of the Fluval 405 External Filter is 383 gallons or 1450 liters per hour, which means that it has more than enough cleaning power for any aquarium.

This model comes with an instant prime system for easy and hassle free startup. What is also great about the Fluval 405 is that it features an intake clog prevention system so the filter doesn’t suck up larger pieces and get clogged. This model features improved motor performance when compared to previous models, making it much more reliable, efficient, and long lasting. The Fluval 405 External Filter is also fairly quiet so it won’t disturb you or your fish. The sound dampening impeller helps make it even quieter. This model also comes with an aqua-stop valve to ensure that it is both air and water tight.

We do like the fact that this is a fairly compact external filter. It easily clamps on to the exterior of your fish tank using the single motion lift lock clamps. It is easy to place wherever you want it to go and the clamps make attaching it even easier. The Fluval 405 External is a very quiet, efficient, reliable, durable, and highly functional external filter that will clean your aquarium water while not taking up any room inside of it.


  • Powerful 3 stage filtration.
  • Filtration can be customized.
  • Fairly quiet.
  • For aquariums up to 100 gallons with 383 GPH flow rate.
  • Aquastop valve for water tight performance.
  • Filter to stop clogs.
  • Easy to attach and remove.


  • The impeller starts to wear down after ½ year of use.
  • Lid is not easy to remove.

Check the price at Amazon

Fluval 405 External Filter Overview

The Fluval 405 is quite similar to the Fluval 406, but with some key differences. Let’s take a good look at the Fluval 405 External Filter to see what it is all about.


The Fluval 405 External Filter is meant to service aquariums of up to 100 gallons in size. It is more than powerful enough to handle some very large fish tanks as it can pump put over 340 gallons of water per hour. Just like with the Fluval 406, the Fluval 405 can hold up to around 40% more water than other canister filters of an equivalent size, thus making it very space efficient and effective too.

Also, just like with the Fluval 406, the 405 has an aqua-stop air valve in order to ensure that it is both water and air tight. This means you can disconnect the hose without stopping the suction, thus removing the need to prime it again. This model also comes with an instant prime mechanism so you don’t have to manually prime this filter every time you start it up.

Also, just like the 406, the 405 features a customizable filtration system with removable baskets so you can add your own filter media. This bad boy gives you great mechanical, biological, and chemical filtration to keep your aquarium as clean as can be.

What we really like about the Flival 405 External filter is that it comes with a special overheat protection system to protect the motor from heat damage. What is also pretty neat is that besides the impeller there are no moving parts, making it a very durable option to consider.

Simply put, the less moving parts there are, the less parts there are that can break. Of course, this is an external filter so a big bonus is that it does not take up room inside of the fish tank.


  • Fairly high flow rate.
  • Meant for large aquariums.
  • Great 3 stage filtration.
  • Easy to use.
  • Air and water tight seal.
  • Overheat protection.
  • Easy prime feature.
  • Saves space.


  • Somewhat loud.
  • Impellers may wear out after prolonged use.

Check the price at Amazon

If you need some more heavy duty options for larger thanks then check out this post.

Our Verdict

In all honesty, both the Fluval 405 and the 406 make for excellent filters. We don’t really want to make a value call here or influence your judgment too much. Both filters do their job fine, but they just have minor differences.

For instance, the 405 can handle less water and is a loud, but the 406 doesn’t have overheat protection. There are just some tradeoffs that you need to think about. In terms of coming to a final decision, we will leave that to you but both are decent options.