5 Best Biological Filter Media for Aquariums

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Any aquarium needs a water filter that does its job well. But owning a good filter is not everything. As you probably already know, a water filter can do 3 types of filtration: mechanical, chemical and biological.

In this article, we will talk about biological filtration and why it needs to be present in any filter device. Later, I will tell you about the 5 best biological filter media for aquariums.

Benefits of Biological Media

First, I will tell about the 2 most popular benefits that come with using a biological filter media.

As a first advantage that comes with using biological filter media in your aquarium, is the cleaner water that results from this process. How does it happen?

All fish tanks need to be cleaned, and the water has to be filtered. But there are certain things you can’t get rid of in a traditional manner. For example, while your fish live happily in the aquarium, harmful ammonia, nitrate and nitrite is accumulating in the water. These are all residues from the fish.

In bigger quantity, any of the three will be harmful to the wellbeing of your fish. This is where the bio-filter comes into the picture.

A biological filter media will remove all these harmful substances from the water. How? A biological media contains bacteria colonies that must consume ammonia, nitrite and nitrate. While the bacteria in the media thrive, the chemical mentioned above are removed from the water.

Basically, a biological media is the housing for the bacteria colonies that clean your water. So, the first advantage of using a biological media, is the fact that your fish will live a healthy life, due to bacteria colonies that are eating up the bad chemicals from the environment.

The second advantage that comes with using bio-filter media is the fact that it’s very simple to use. This is because most bio-filter media can be directly placed inside the mechanical filter that you already own.

This means that if you already have a water filter bought, you can simply place the bio-media inside the device where it’s supposed to be. The rest is done automatically.

Next I will tell you more exactly how this media is supposed to be set up:

How to Setup Bio Media in the Filter?

Setting up this stage of filtration is easier then you may think. The first thing you must do, is choose a filter media that think is best for your specific aquarium (I will list the 5 best bio-media a bit later. You can choose any of these).

Once you have the media bought, you just have to open the filter and place the media where it’s supposed to be. Now, this depends mostly on your personal filter.

That’s because there are multiple types of water filters: hang on back filters, canister filters, underwater filters and others too. To find the right spot in your device, just take a look in the user manual, or make a quick search online. You’ll find it in no-time.

There’s one important aspect you should keep in mind though: since any bio-media consists in bacteria colonies, you have to make sure they grow and thrive in your aquarium. Choose a bio-media that lets water flow through it easily, and the colony will live longer an thrive in the environment.

Let’s move on now, and see what the 5 best bio-media filters are for your aquarium:

1. Biohome Ultimate Filter Media

This is the first pick on our list. You can find this media, and all the others on Amazon. What’s in it for you? Let’s see!

The package I’m introducing here contains 2 LBS of biological media that’s enough for 20-30 gallons of water. So, even if you  have a bigger aquarium, you’ll be all set.

Something great about this product is the fact that it works with most types of water filters. Canister, hang on back and sump filters will pose no problem.

Also, it helps you grow easily the bacteria colonies, without the need of special knowledge. Due to this, you’ll have an odorless and clear water in a relatively short period of time. Of course, it will get rid of all the ammonia and nitrates in the fish tank.


2. Seachem Matrix Biological Media

This is the second item that’s worth checking out. It’s a very porous media that provides excellent biological filtration in all types of aquariums.

By all types of aquariums I mean ALL types. This is actually a great advantage about this product. You can use it in fresh water, salt water and reef aquariums as well. The pH value of the system it’s used in, will not be affected.

One liter of Matrix media is enough for 40 liters (10 gallons) of water. So, if you buy this version, you get enough bio-media for a 20-gallon fish tank.

The material of which this media is fabricated from is a naturally mined substance that will facilitate the growth of the bacteria colony. Because this media is organic, the size, coloration and shape could vary slightly, but this is to be expected. Even so, the material is a quality media used by lots of people world-wide.


3. Eheim Substrat Pro

This product is made from sintered glass. Basically, they’re artificial porous pearl-shaped glass. This media is created to be used in Eheim filters, like the Eheim Classic, Pro 3 or Ecco.

It’s worth mentioning that you can reuse this product by rinsing it lightly with aquarium water in every 1 to 3 months. But also, you can replace it every 3 to 6 months, if you think it’s better for the water environment. As you can see, the intervals between maintenance are quite long.

It has an open structure, which comes with a big advantage: it lets the water penetrate the media way easier. Because of this, the bacteria colony will grow quicker and you’ll be able to filter the water biologically sooner.


4. Fluval Biomax Filter Media

The Fluval Biomax is great for all types of filter devices. Even though that’s the case, the product is crafted to work best with fresh water aquariums. If you are one to possess such an aquarium, you can use this bio-media to get rid of all the ammonia and nitrates in the water.

Many breeds of fish can die quickly if there is too much contamination in the water. That’s exactly why Fluval has developed a special filtration system, that works wonders in fresh water environments. These types of fish are more likely to get sick sooner, so this comes as a great help.

I said above that this media is specially crafted for fresh water aquariums. Even though that’s true, you can use it efficiently with marine life as well. In such tanks, the media will quickly balance the water content, so everything is in sink.


5. BrightWater Aquatic Bio Media

The BrightWater bio-filter media is the last product on our list, but that doesn’t mean it’s the worst by any means. Besides the standard ammonia and nitrate removal property, it also comes with Ion exchange.

This is a welcomed feature for a good reason. If you own an aquarium, you want your fish to thrive in it , right? Well, that’s exactly where the Ion exchange steps in. It helps increase the appetite of your fish and also improves their activities.

The media itself is made of a ceramic material that is completely non flaking and 99% dust free. The design is circular and it has an optimum pore structure that lets water flow through it easily. This will help the bacteria colony grow and thrive.

Also, the media is suitable for fresh water and sea water aquariums both.



We reached the end of today’s article. What did we learn from it? At first, I talked about the importance of having a biological filter installed in your aquarium. There are at least 2 major benefits that comes with using this type of filter.

The most important one is that a bio-media will remove all the ammonia and nitrates from the water, that could sicken your fish. So, it’s of utmost importance to put in place a bio-filter.

Also, you should have a pretty good idea on which bio-media is best for your needs. That’s because a talked about the 5 best biological media for a fish tank.

Choosing the best is really up to you. Think well about your specific needs, so you can see which media is best suited with your personal aquarium. After all, what is good for someone, might not be for another person.

One thing is certain however: all of the 5 bio-media listed above have quality properties that make them great at getting rid of biological debris.

Featured Image: Flickr

Author Image Fabian
I’m Fabian, aquarium fish breeder and founder of this website. I’ve been keeping fish, since I was a kid. On this blog, I share a lot of information about the aquarium hobby and various fish species that I like. Please leave a comment if you have any question.
Questions and Answers
jim gerard July 5, 2020 Reply

API’s Biochem Stars are bertter than all of these yet are never mentioned anywhere anymore

I use it for over 1 year now in my Hang-on Filter, Clearview 2

A Sponge in the bottom; and an Eheim Bio in the little and on top a Matrix. Clean water all the time plus all perimeters on the TOP.

100% Recommended.

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