Aquarium fish tanks are a beautiful thing, but they can be even more enchanting if you take care of them correctly. Biological filter media plays an integral role in maintaining the balance in your aquarium to preserve a healthy environment.

Aquarium owners all over the world wonder what is the best filter media to keep their tank clean. There are many different types of biological filter media and it’s important to know which one will work for you.

I have picked some of the best biological filter media available on the market from top brands as well as the most efficient and cost-effective ones.

What Is Biological Filter Media?

A biological filter media is made out of porous material that acts as an inert housing for a colony of beneficial bacteria.

Biological filtration is one of the most effective forms of treatment for aquatic life as it removes toxic chemicals, like ammonia, nitrite and sometimes nitrate. It also helps to keep the tank clean.

10 Best biological filter media: An in-depth review

There is no debate about whether aquariums need to have a filter media or not. The question is what should you get? The number of options available are way too many.

Best Biological Filter Media

To help you out, please allow me to introduce some of the best biological filtration media for your aquarium. Here, you’ll find reviews on some of the most popular brands in the industry. This will help you make an informed decision.

1. Seachem Matrix – Best Bio Filter Media For Aquariums

Seachem Matrix Review


The Seachem Matrix Bio Media is considered a standout amongst other biological filter media for aquariums.

This bio-media ensures that nitrogen wastes are removed in your fish tank or aquarium effectively. However, you don’t have to be concerned about losing the filtering capacity or the necessity for replacement. The product is usable in any filter, although it works best in canister filters. It is big enough to use without a filter bag.

To prevent any kind of breakage, this product is specially developed with high porosity including a solid structure, which sets it unique from other bio media.

A single liter of the matrix can cover as much space as 170 liters of plastic balls, while only being 10mm in size. Plus the surface it provides is macroporous. Macropores are great for housing nitrifying bacteria, as well as denitrifying ones.

So, you can get rid of ammonia and nitrates plus nitrites using a single filter. Furthermore, you need minimal attention for maintenance.

Surprisingly, this media is a chemically inert, naturally mined substance used to let biological filtration develop in aquariums and ponds settings. It can also vary mostly in height, structure, color, and volume because of its organic structure.

  • Perfect for accelerating the growth of denitrifying bacteria
  • It has the potential to maintain water quality
  • It comes in such a size that fits almost all the filters
  • Offers great amount of surface area
  • It does not function with a drip tray system

2. EHEIM Substrat Pro Biological Filter Media

EHEIM Substrat Pro Biological Filter Media

EHEIM is a brand you ought to be aware of due to its incredible Aquarium setup as well as other robust equipment. Guess what? This Filter Media from this world-class manufacturer is usually regarded as one of the best biological filter media. Well, let us take a look at some specific features.

Firstly, if you require a high-quality bio-media, EHEIM substrate is the finest option. Unlike traditional natural media, the EHEIM substrate is made of porous artificial glass. Also, this sintered-glass media has a spherical form, which allows for more extensive colonization of good bacteria.

Having that kind of a heavy proportion of bacteria means you will get fewer nitrate burdens as well as a healthier aquatic environment. It has a surface area of about 1800 square feet per gallon, which is sufficient for an aquarium tank.

Despite the fact that EHEIM manufactures its line of biofilter canisters, the EHEIM Substrat Pro BFM can be used in any type of canister filter tray. This item is ideally suited for bigger canisters in both marine and freshwater aquariums.

Without being changed, EHEIM substrate pro-bio-media typically remain for three to six months. It delivers a lengthy period of maintenance due to its artificial character. On the contrary, regular biological media cannot beat it.

  • Provides extended maintenance periods
  • For intensive colonization, a high-density spherical form is used
  • Because of its artificial character, the bio media is easy to clean
  • After 3 to 6 months, needs replacing on a regular schedule

3. Biohome Ultimate Filter Media

Biohome Ultimate Filter Media

Here is yet another essential and great piece of high-quality bio-media. In the aquarium field, Biohome Ultimate Filter Media is regarded as a top professional media. The product I am presenting here comprises 2 lbs of biological media, which is enough for 20-30 gallons of water. And you’ll relax even if you have a larger tank.

It is composed of sintered glass, which is a mixture of silica sand and recycled glass that is then oven burned. This procedure yields a pellet that is very porous and has ample places for bacteria to grow.

The material has a rough surface and is extremely porous. This is ideal for bacterial growth. Every aspect of this media has a potential role. It maintains the optimum bacterial ecology in the tank.

These bacteria function as filters, removing ammonia, nitrate, and nitrite from the tank water. Aerobic bacteria thrive in the outer zone, whereas anaerobic bacteria thrive in the interior zone. It may surprise you to know that it is the only bacteria capable of reducing nitrate levels. Here, it just takes a little time for them to demonstrate efficiency.

Otherwise, you just need to change the water frequently. This is the most effective method to maintain nitrate levels low in the absence of bacteria.

  • Assists in the growth of nitrifying and denitrifying bacteria
  • Produced from natural and recyclable materials
  • Pellets are tiny enough to fit through the majority of filters
  • Just functions as a biological filter media

4. CerMedia MarinePure 1.5-Inch Sphere Bio-Filter Media

CerMedia MarinePure 1.5-Inch Sphere Bio-Filter Media for Marine and Freshwater Aquariums

If you want to minimize the contaminants in your aquarium, you may strongly consider using this MarinePure CerMedia. This is a product of the Marineland brand. So, you can have faith in its quality to deliver satisfying performance.

The Media comes with a large surface area and open-flow porosity. It can eliminate ammonia nitrite from your aquariums.

The surface area of one MarinePure Sphere is equivalent to 1350 plastic bio-balls.

Another interesting feature of the media is it is suitable for instant filters, sump filters, even a dry filter.

You can fit it comfortably in your filter and enable water to flow freely through while preventing particulates from slipping through and damaging your equipment. It was created using Inert Ceramic.

Additionally, the media has no negative effects on the water’s properties. So you are free to use it in both saltwater and freshwater aquariums.

This unique feature boosts the system’s filtration and purifying process. Overall, this bio medium is astute in guaranteeing that all trash and floating particles are completely collected.

  • Reducing nitrate level
  • Preferable both in freshwater and saltwater aquarium
  • Inert part is made with ceramic
  • Not so porous like matrix or substrat pro

5. Fluval Biomax Bio Rings

Fluval Biomax Filter Media

Fluval is a well-known brand among aquarists for producing high-quality goods. The Fluval BioMax gives a broader surface area for biological filtration in your aquarium, allowing denitrifying and nitrifying bacteria to colonize.

The best part of the product is, it has a porous ring, which is made of aluminum oxide and silica. These bio rings are hollow ceramic cylinders that have been formed in an inert state. Also during the process, these cylinders are not flattened or burnished. Which results in a rough, porous form.

Surprisingly, the ring shape lets water flow through more rapidly. This filter’s sophisticated pore structure not only enhances the survival of helpful bacteria but also speeds up the colonization process and allows for deeper cleansing.

Another intriguing feature is that the filter functions both in marine and freshwater tanks. This indicates that the filter is powerful enough to prevent mosses from sprouting in the aquarium.

However, the media contains more area compared to other filter media. It features a hole in the center that allows water to pass properly. It has been designed specially to provide the best possible contact time for your tank’s biological filtration. To facilitate appropriate seeding, simply refill half of the filter media at a single period. Amazing, isn’t it?

  • Denitrification and nitrification are both possible with this material
  • Long-lasting and simple to take off
  • It is comparatively affordable
  • It occupies a significant amount of room

6. Fluval Foam Filter Block

Fluval Foam Filter Block

Here comes another Fluval product, containing some fresh and distinctive features. The product is particularly meant to fit Fluval 404, 405, 406, and 407 aquarium filters. The Fluval 306 or 406 bio-foam comes with two smaller bio-foam portions that go into the sections of the lower part of Fluval canister filters.

The Fluval Foam Filter Block efficiently eliminates big particles and trash from your aquarium to allow proper mechanical filtration. Even though mechanical filtering is the principal function of the Fluval Foam Filter Block. However, biological activity can emerge inside its porous system at some point.

Its highly porous nature enhances the surface area for beneficial nitrifying bacteria to thrive on. It also captures tiny particles which foam filtering failed to trap at the beginning.

Additionally, this media provides a second layer that improves biological filtration. Even for long-lasting filtration, the appropriate pore size facilitates effective water movement with minimal blockage.

  1. To avoid waste bypass, it’s custom-made
  2. Suitable for use in both marine and freshwater settings
  3. The 2-pack style is super handy
  • You can’t use it filters other than Fluval.
  • Not so efficient for biological filtration. You will need other bio filter media to add in your filter.
  • Replacement required every 6 months

7. Aquatic Arts FilterPlus Bio-Media Aquarium Filter

Aquatic Arts FilterPlus Bio-Media Aquarium Filter

Among the most popular forms of bio-media in the aquarium world is Aquatic Arts FilterPlus Bio-Media. This aquarium media not only provides 100% natural but also it is free from toxic substances, dangerous chemicals, or contaminants. It has no side effects on aquarium water.

The ultra-porous surface area of FilterPlus is the key to its outstanding Bio-Filtration capabilities. Compared to ordinary Bio-Balls or ceramic rings, this delivers a considerably larger surface area for each unit of volume.

It also beats conventional filter options like bio-balls or ceramic rings by a significant margin.

Also, It can support anaerobic bacteria, which is essential to control the water quality. It will never require any replacement. As a result, these Bio-Filters let you be headache-free and save a lot of money.

With or without media bags, these media have the potential to use any type of filter. You can directly insert it into the media chambers of your filter. Its sophisticated structure lets you fit it with nearly all sorts of filters, such as hang-on filters, canister filters, and also in the Bio-Filtration substrate it works flawlessly.

Around 150 holding aquariums and 10,000 aquatic animals benefit from this Biofiltration media, this is aquarium arts’ best creation.

  • Natural in every way, no added chemicals
  • Require no replacement at any time
  • Allows for a larger amount of stocking
  • Having the possibility to get dusty at some point

8. Fluval G-Nodes Biological Filtration Media

Fluval G-Nodes Biological Filtration Media

Fluval Bio-Foam is a biological and mechanical filtration media developed specifically for Fluval aquarium canister filtration. The right pore size provides effective water movement and a longer lifespan for the media.

Even, A six-month supply of mechanical and biological filtering media is included in this full savings box. This affordable bundle includes all of the essential elements to maintaining your canister running well for several months.

The Fluval value packs are meant to work with the 306 and 307 external filter series. With all of the quality, efficacy, and simplicity, you can expect wonders from this world’s leading aquatic filtration company.

Therefore, this media’s primary function is to capture bigger particles throughout the coarse pads, resulting in a fresh, clean, and productive system. Its strong structure is also suitable for collecting undesirable tiny particles.

Besides, Its massive surface area encourages the growth of good bacteria and keeps the aquarium safe and hygienic.

This unit is appropriate for both freshwater and saltwater aquariums. It has the potential to prevent debris bypass. Moreover, Its unique foam mechanism ensures that water flows consistently. So relax!

  • 2-pack design is super convenient
  • To avoid debris passage, each piece is custom-made.
  • Increases biological filtering
  • Offering only 6 months of support

9. API BIO-CHEM STARS Filtration Media 20-Count

API BIO-CHEM STARS Filtration Media

API BIO-CHEM STARS biological media is used to support the growth of large colonies of nitrifying bacteria, which convert toxic ammonia to nitrate.

It can also help to build and implement a healthy aquatic habitat in your freshwater or saltwater aquarium, as well as in reef tank aquariums.

This biological filter media is called API BIO-CHEM STARS because of its idiosyncratic structure. It also enables the mos efficient oxygen and water transmission through the star, ensuring that bacterial colonies remain healthy and active.

A 50-70 micron internal pore network is formed using a proprietary manufacturing method. Surprisingly, the pore system gives four times bigger surface area for bacteria colonization than ceramic rings.

API Aquarium Treatment Supplies are built to operate together so that they can deliver the highest performance for controlling algae, promoting healthy bacterial development, and assisting in the prevention and treatment of fish illnesses and disorders like as ich and fin rot disease.

They endeavor to create a safe and welcoming habitat for aquarium fish such as cold water or tropical fish. Ideal for new aquariums. But, you can also use the media for the cleaning program because it does not degrade or block filters.

  • Create four times bigger surface area
  • Modern polymer material with appropriate pore size
  • Suitable in both freshwater and saltwater aquariums
  • Not recommended for hang-on-back filters

10. AQUANEAT Bio Ceramic Rings Aquarium Sump Filter Media

AQUANEAT Bio Ceramic Rings Aquarium Sump Filter Media Fish Tank

Finally, we’ve arrived at our final filter media. It is none other than Aquaneat Bio Ceramic Rings. Have you ever heard of Aquaneat? It’s a well-known brand in the aquarium marketplace, yet its filter media is quite famous for its effectiveness including long-lasting features.

These bio-media rings are designed to maintain your aquarium water crystal clear. Plus, it has the capability of delivering excellent biological filtration. Even the ceramic media has a high porosity enabling beneficial biological filtration.

This media comes in 6 packs of compact ceramic cylinders which can stimulate the growth of beneficial bacteria in the tank providing a happy and healthy environment.

The washable media bag features a zipper design. As a result, the filter rings can be kept securely in the aquarium tank. It’s suitable for both saltwater and freshwater aquariums.

Since it is formed of solid ceramic, you do not have to worry about floating the media on the water surface. It has made it flow only on a deeper level. This filter media, therefore, needs to be cleaned before use. This also includes a free media bag for convenient transportation.

  • The ring offers enough room for suitable bacteria colonies to flourish
  • Cleans phosphate and ammonia properly
  • Not necessary to clean regularly neither replace frequently
  • Require to purchase six bags at the same time

Biological Filter Media Buying Guide

Choosing a random bio-filter media may degrade the circumstance of your fish tank. Here I will take you on a short tour of what to look for and the key factors for finding the best biological filter media.

If you keep these in your mind,  no seller can manipulate you into buying their products and you’ll become a hardheaded buyer soon.

Surface Area of the Bio-media

Firstly, check how much surface area it covers. If the surface area is large, then more beneficial bacteria will be able to live there. But the surface area doesn’t actually depends on the size of the media. It is the surface of the micropores it has inside!


Bio-filter media is available in bio balls, bio stars, sponges, pads, rings, and gravel. The interesting thing is those materials are also used in the mechanical filter media. Different materials offer different functionality and level of filtration.

Experts say bio-balls, ceramic, and pads are preferable.


As we all know, high-quality products always cost higher than average products. This is true but not applicable for all purposes, what you need is efficiency.

Sometimes an expensive biological filter will give you diminishing results compared to the investment, while a budget-friendly product can serve you with the best and save your wallet.

Always, look for quality and specifications and weigh them against the price and see. You need to be vigilant in this case.

Bio-media Nature

The shape of the bio-filter media plays a huge part. Most of the users prefer circular, oval, or spherical shape bio-filter media because they provide a high bulk-density. Big-sized bio-balls are the perfect match for large tanks, and small-sized bio-balls are preferable for smaller ones.

How to Setup A Biological Filter Media?

I hope you have already gone through all the reviews I talked about above. You have made up your mind, right? Now you know which bio-media is suitable for your aquarium. Then it’s time to learn how to set it up:

You should always place a bio media before placing the chemical media and after the mechanical press. Always prevent your bio-media from being clogged. Because, if it happens, the Oxygen supply will get cut off and the bacterial colonies will be on the verge of death.

You see, bacteria production is very important for the aquarium. It kills toxic and harmful substances in the tank and keeps continuing the nitrogen cycle.

Normally, nitrogen cycling takes at least 30 days. After that, your filter will be well-balanced. The nitrogen cycling could possibly last for years as long as there is enough food for the bacteria to thrive. You also have to make sure that the media is rinsed properly to avoid clogging.

To setup the media you need a filter to run the whole system. It could be a sump filter or a canister filter or a HOB filter or even an internal power filter. Most preferable choice would be the sump or a canister. If it is a canister filter then put mechanical filtration media like foams or synthetic cotton in the first chamber. Then in the second chamber put the biological filtration media. Same is applicable for sumps or other filters as well.

Check out our guide regarding the nitrogen cycle in an aquarium from here.

What are the Benefits of Biological Filter Media?

Having biological filter media in your aquarium means many things you are free from the to-do list. Which leads you to minimize your solicitude. Let me tell you how.

Certainly, biological media provides numerous advantages. I am going to inform you about some of the most common advantages of having biological filter media.

Clean water

With a biological filter media installed, not only your fish get healthy surroundings but also your aquarium gets clean and fresh water.

Assists in the filtration

Secondly, Bio-filter media helps the beneficial bacteria thrive, in return they keep the aquarium clean by helping out at filtering components. It is the most effective at removing all of the harmful substances from water.

Are you familiar with the procedure? If not, let me explain it to you.

Certain infinitesimal substances are impossible to get rid of in the usual way. While your fishes are joyfully swimming in the aquarium, pestilent ammonia, nitrate, and nitrite are aggregated in the water and build a toxic environment. These are mainly from the leftover food by the fish.

Furthermore, fish waste also produces ammonia and nitrates into the water, as do a variety of other decaying components. You need to get rid of the a.s.a.p, and the biological filter plays a quintessential role in that.

Bio-media helps to develop a bacteria colony that provides an endless supply of bacteria. The bacteria control ammonia in the tank by naturally breaking it down and absorbing the excess ammonia, nitrite, and nitrate from the water, so it acts as an endless cycle of natural filtration.

Suppresses algal growth

Wondering how that happens? Let me tell you. I mentioned before that excess ammonia could be present in your tank. Well, whenever there are excess nutrients, it’s bound to attract algae. And having too much food for algae means you’ll be experiencing algae bloom eventually.

Now, breaking down ammonia into harmless compounds and absorbing them has one other benefit- the algae don’t have enough food to thrive. So it’s like a 2-in-1 deal!

Natural and non-toxic filter

Finally, because of its unique characteristics, bio-media is an amazing option for filter systems. It is necessary for balancing the bacteria growth in the aquarium while keeping the tank non-toxic. Thankfully, Bio-media has the advantage of having no harmful impacts on aquatic animals. The best part is, it has no side effects.

It’s completely natural, therefore has no adverse reactions.

Why Do People Prefer Biological Media over Other options?

Nowadays bio-media is becoming popular among customers. The reason is simple, it is designed with less complexity, which provides more flexibility and is easy to set up.  The majority of the time, you can just put it into the mechanical filter directly.

Therefore, during the installation process, you will be tension-free. Whether, you already have filter media, and then simply place it inside the existing filter. So, that’s it!

Biological media is a natural way to keep your aquarium’s water clean. Bio-media is a hole in the water that contains harmless microorganisms which make water free of pollution, dirt, and hazardous substances.

Moreover, the safest sort of media is biological media that is why people choose it. As fishes can become trapped inside the mechanical media and die, beginner aquarists should avoid mechanical media.

Although chemical media is not hazardous, it does contain chemicals. It’s impossible to predict when your fish may become allergic to the toxins. These are the primary advantages that lead individuals to choose biological media.

Also, it doesn’t take too much space, like a mechanical filter. So you have more area to focus on the aesthetics of your aquarium.

How to Clean Biological Filter Media?

You should clean your biological filter media only when it’s most necessary. Unlike other tools, frequent cleaning is detrimental here as it’ll stop colonies from thriving.

First, you need to open the filter media to examine whether it is dirty or not. If there is an abnormal amount of sludge, checkout the filtration system carefully. If it’s too much, then you follow these:

1. Change the water partially

First, you extract some water from the tank, then load it into a bucket. Now we take out the biological filter media and place it on the bucket. It’s because if you clean your filter media inside your aquarium, the filth will remain inside the tank. So the tank water will become dirty.

Here, using supply water is not a good choice as it will harm the media. Because supply water often has chlorine. So, you have to use the tank water where your media is placed.

2. Rinse gently

Now, you start rinsing the filter media slowly with the aquarium water. Make sure not to scrub hard otherwise you might lose beneficial bacteria.

Remember, using detergent or chemicals to clean biological filter media will harm the bacteria colony. Bleach is also a big no no.

3. Place it back in the tank

After you’re done gently rinsing the media, you finally have to put the filter media back into your filtration system just the way it was before. There is no need to wait for the media to dry. Your filter media will look as good as new.

When to replace Biological filter Media

All filters eventually will have to be replaced. But knowing when to do it is hard to understand.

There is no particular time duration of replacing a bio-filter media. Even its makers don’t instruct anything like this.

A Bio-filter media’s durability is indeed much longer than a mechanical filter. Unlike a mechanical filter, you don’t have to touch it at all unless it stops functioning properly. When the filter media causes problems- like getting clogged up, only then you try to replace it.

If there are no problems, then I’ll suggest you keep the media until it fully breaks down. Anticipate when that’s about to happen and put new media on the same tank so that the bacteria can colonize the new one, this way, they’ll have a new home fully prepared.

Frequently Asked Question

How often should you clean filter media?

Biological filter media should only be cleaned on a limited basis and with extreme caution. Whereas do not ever wash it using chlorinated tap water, since this will destroy all of the bacteria in your aquarium.

What Should Be The Proper Amount Of Biofilter Media?

To proceed, you must first measure the particular nitrifying rate per surface area or volume for your biofilter media. If the manufacturer recommends a specific usage rate, you should stick to it. However, if you need extra media afterward, you can add more.

How Often Do I Need to Change My Biological Filter media?

You don’t need to change your biological filter media at all unless they’re clogged. You should leave them be until then.

Can Sponge Be Used as Biofilter media?

The answer is yes at a certain condition. While purchasing sponges for your aquarium, take extreme caution. Some sponges are not suitable for use as filters. Cleaning these sponges at various stages is also important. Otherwise, you will simply disrupt the bacteria in your aquarium.

Final Thoughts

It might be difficult to find the perfect product for everyone. Each has their own preferences. For example, I love the Seachem matrix for its nitrifying and denitrifying properties, but others might want something else.  Just like them, you need to find what criteria you should prioritize first.

I hope the review article has covered all you need to know to make sure you purchase the best biological filter media for your aquarium.

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