Buying the best biological filter media is very important for the overall hygiene of your fish tank. However, finding an ideal one can be confusing for many aquarists.

To make your decision-making easier, we have compiled a list of the best biological filter media that will keep your tank water hygienic and clean. Check them out.

Comparison Chart

Name Color Size(in gram) Customer Rating (Out of 5)
Fluval Biomax Filter Media

White One size – 500 4.8
Brightwell Aquatics Xport BIO Cubes

Beige / Brown Six sizes –

(500 s- 2000)

EHEIM Substrat Pro Biological Filter Media

White One Size – 2000 4.8
GOLDEAL Bio Balls Ceramic Rings Set

Multicolor (neutrals) One Size – 500 4.4

Best Biological Filter Media: A Detailed Review

1. Fluval Biomax Filter Media


  • Has a wide diameter for optimal bacterial contact
  • 100 percent safe for your fish
  • Only half the filter fills up in one cycle, which increases the device’s durability
  • It is compatible with all filter sizes
  • Applicable for freshwater and marine water aquariums
  • Has excellent customer ratings and reviews


  • Less quantity compared to competitors
  • Slightly more expensive in comparison to alternatives

Fluval Biomax is one of the oldest biological filtration media in the market. It is best known for its sturdy ceramic ring design that gives it a six-month lifespan which makes it one of the longest-lasting filter media in the market.

It is porous in texture and is structured to allow the water to pass through the filter while giving it the optimal time to come in contact with beneficial bacteria for efficient biological filtration. This ensures that all the ammonia and nitrate present in the water is removed, making it hygienic for the fish.

Even after an extended period of use, Biomax filter media does not lose its shape and maintains its efficiency throughout its intended lifespan. The rusty and uneven texture provides an ideal site for bacterial colonization which promotes the breakdown of toxins to clean the water.

We like this filter media because it is compatible with most filters in the market, and you can also use it in both freshwater and saltwater aquariums. Even though the amount of filter media provided in this package is less in quantity and slightly more expensive as compared to other products, its long lifespan, and superior quality compensated for it.


The Fluval Biomax Filter Media is an ideal choice for you if you are looking for a reliable and durable filter media with a highly efficient filtration rate. It is a perfect choice for both saltwater and freshwater tanks and can be added to tanks of all sizes.

2. Brightwell Aquatics Xport BIO Cubes Ultra-porous Biological Filter Media 


  • It comes in multiple sizes
  • Brightwell Aquaticsuses NanoIntelex Technology creates a greater surface area
  • It can be used in both freshwater and saltwater aquariums
  • Affordable pricing across all sizes
  • This brand provides the highest conversion rate compared to all alternatives
  • Optimally neutralizes the pH level of the water


  • The smaller pieces crumble up and dissolve faster than expected, making the product slightly less durable
  • Relatively more expensive

Brightwell Aquatics Xport Bio Cubes are one of the most efficient aquarium biological filter media available in the market today. This is because they are made using NanoIntelec technology which gives them an enhanced surface area. In fact, they have the highest surface area to volume ratio in the biofilter media market. This helps them filter out even the smallest particles that can be harmful to your fish.

This filter media comes in the shape of small cubes that do not need to be placed in a filter. Instead, you can simply drop them in your tank. They take up less space in the tank while providing highly efficient cleaning.

Their efficiency depends on the pH level of the water as well so make sure the pH stays around 7.5 to get the best results. However, they need to be seeded with appropriate bacteria first to begin denitrification.

You only need to use 2 to 4 cubes for every 10 gallons of water depending on how dirty your water gets. These cubes start working instantly after being added to the tank and denitrify the ammonia and nitrates present in it.

The cubical structure provides a larger surface area per unit, which in turn, increases the denitrification rate, providing quick and noticeable results. To further enhance the cleaning rates and add minerals to the water, you can use them alongside Xport NO3 and PO cubes.

The increased efficiency has a minor trade-off, which makes it slightly less durable as compared to other options and it slowly dissolves within a few months of use. However, it is balanced off by its reasonable price. This filter media is available in 6 different sizes ranging from 33 oz to 5.28 gallons to cater to your specific needs.


Brightwell Aquatics is one of the only brands that use the NanoIntelex Technology for denitrification and also the only brand which provides the highest ammonia to nitrate conversion rates. It is suitable for larger aquariums since the increased efficiency can easily clean up large quantities of water.

3. EHEIM Substrat Pro Biological Filter Media (Sintered Pearl-Shaped Glass)


  • This product requires less maintenance
  • It is longer lasting
  • Can be reused multiple times after a rinse
  • Increased surface area results in better bacterial colonization
  • It is simple and easy to use
  • It has a perfect size that does not hinder with other components of the tank


  • Requires you to purchase filter if needed in certain tanks
  • Expensive compared to other options

EHEIM is a highly rated, trustworthy brand that caters to the needs of all aquarium enthusiasts. Their filter media, Substrat Pro, is best known for its perfect size and pearl-shaped structure made of highly porous artificial sintered glass.

This filter media has a surface area of 1800 sq ft per gallon due to its advanced structural design. This makes Substrat Pro an ideal site for bacterial colonization and biological filtration. Another great feature that makes the EHEIM filter media stand out from the competition is that it can be reused.

All you need to do is lightly rinse it with water every one to three months and it becomes as good as new. Substrat Pro has a decent lifespan and needs to be replaced every three to six months, which is significantly more than the industry standard.

Its spherical shape facilitates dense bacterial colonization, and the large surface area increases the rate of nitrate and ammonia breakdown. For customers on a budget, this filter media can be a little expensive. However, the fact that it can be reused definitely makes up for its price tag.


If you are looking for a filter media that does not require regular maintenance or replacement, the EHEIM Substrat Pro is the best option for you. You only have to replace it every three to six months. Plus, it is reusable.

4. GOLDEAL Bio Balls Filter Media with Mesh Bag


  • It is the most affordable option on this list
  • It can also be used as decor and accessory for your tank
  • It helps balance the pH of the water
  • Increased surface area results in better bacterial colonization
  • They form an ecological cycle that helps maintain a hygienic and clean tank environment
  • 100 percent refund provided if the customer is dissatisfied


  • Getting more types of filter media also mean that you get lesser quantities of each
  • Some packets have fewer bio balls and more rocks

Goldeal Bio balls set is a unique biological filtration media that comes in various shapes and sizes. An ideal Goldeal Bio Balls purchase consists of 12 kinds of filter media that are scientifically configured to create a rational mixture that provides optimal biofiltration.

These include volcanic rocks, medical stone, zeolite, coral sand, nanometer bacterial rings, infrared bacterial rings, biological beads, bio balls, activated carbon, infrared microspheres, ceramic rings, and red breathing rings.

These varieties of filter media not only work to clean the water but also to provide an aesthetic look to your tank. Apart from being visually pleasing, the different types of filter media are very efficient in bacterial colonization.

Goldeal Bio balls promote the exchange of gases and increase the dissolved oxygen levels of your tank water. Moreover, it purifies the water by collecting the impurities and stabilizes the pH value. This creates a healthy ecological system in your aquarium and promotes a longer lifespan for your fish.


Goldeal Bio balls are the ideal choice if you are looking for an efficient filter media that adds charm to your tank’s aesthetics. The variety of components included in the package helps give your fish tank a diverse look that appears visually pleasing without compromising efficiency.

Why Do I Need a Biological Filter for My Aquarium?

When you clean your tank, the slimy slippery film that covers the entire glass is actually the naturally occurring bacteria. This bacteria is actually very beneficial for your fish as it breaks down the ammonia present in the tank and neutralizes it.

Now you must be thinking that if this bacteria is already present in the tank, then why do you need an aquarium biological filter media at all? This is because when you clean your tank, these bacteria also get removed, leaving your fish vulnerable.

You can think of the filter media to be the safe house that preserves all the bacteria to maintain a balance of nitrate levels in your tank. Moreover, flat surfaces are not very suitable to boost the growth of bacteria as they have a very limited surface area.

This is why biological filter media is designed in a way to maximize the surface area which in turn gives more room for the bacteria to grow safely.

Things to Consider When Choosing the Best Biological Filter Media for Aquarium

1. Design and Structure

The design and structure play a very important role in the case of filter media since the shape decides the surface area which affects its efficiency. Additionally, the rough and uneven texture of filter media further creates a perfect spot for bacterial colonization.

There are a lot of options available in the market that come in different shapes, structures, textures, etc. But the basic principle is common throughout, the greater the surface area of the filter media, the faster the process of denitrification will be.

2. Filter Compatibility

In many instances, the media that you buy is not compatible with the filter. The most common reason is the difference in designs by different brands. To avoid such a situation, it’s best to tally the size of the media with the compatible size range of your filter.

Additionally, you can get away from this hassle by simply choosing a filter media that does not need to be attached with any filters. Filter media like Goldeal Bio Balls, Eheim Substrat Pro, and Brightwell Bio Cubes can simply be left at the bottom of the fish tank as decor while still serving the purpose of aquarium biofilters.

3. Houses Good Bacteria

The primary purpose of an aquarium filter medium is to increase bacterial colonization so that the bacteria can help break down toxic substances like ammonia and nitrate into smaller components so that the fishes and plants inside the aquarium can survive.

Make sure to buy filter media based on their bacterial colonization rate and then look at additional benefits like pH reduction, aeration of the water, and decor. Some filter media can be used as decor, which is a major add-on too.

Biological Filter Media: Frequently Asked Questions

Here are the answers to some of the most frequently asked questions related to biological filter media.

– How Long Does Aquarium Filter Media Last?

How long filter media last is one of the most common concerns as the market is saturated with tons of options, each promising different durations. However, the answer depends on the type of filter media you are using and also the number of fish in your aquarium.

Most filter media have a lifespan of two to four weeks, with some exceptions, such as the Eheim Substrat Pro, which can serve you for three to six months with proper care. Some general indications that your filter media needs to be replaced include noticeable organic buildup in the tanks and rising ammonia and phosphate levels, which can harm your fish.

– Which Is Better: Bio Balls or Ceramic Rings?

Both the filter media categories have their subjective uses. Bio balls usually only contain nitrifying bacteria on their surface. On the other hand, ceramic rings can have both nitrifying bacteria on the surface and denitrifying bacteria on the inside. This makes ceramic rings the more versatile option.

– How Can I Increase the Beneficial Bacteria in My Aquarium?

Beneficial bacterias are every aquarist’s friend. This is because they clean the tank and introduce essential minerals in the water while also getting rid of excess ammonia-based waste. Thus, it becomes necessary to promote their growth. You can do this by :

  • Increasing the water temperature
  • Increasing oxygen levels
  • Turning off the lights
  • Limiting the amount of fish in your tank
  • Adding appropriate biological filter media

Be careful not to add chlorine and chloramine to your aquarium because they can harm the beneficial bacteria and your fish.

– How Do I Clean the Filter Media Without Killing the Bacteria?

We recommend avoiding unnecessary cleaning of the filter media. However, if the filter media is really dirty and requires cleaning, then go for a gentle wash instead of thoroughly cleaning it with anything harsh.

Do not use sponges or brushes for it. Instead, simply rinse it with care to avoid disturbing the bacterial colonies. In addition, avoid soaking them in strong chemicals like chlorine as it will deteriorate its efficiency.

– How Much Biological Filter Media Should I Add to My Tank?

There is no fixed amount of filter media that you need to add to your tank. Putting excessive biological filter media will not make any significant difference apart from slightly speeding up the whole filtration process. The best way to know the exact amount of filter media that you should use at once is by closely monitoring your tank’s nitrate levels.


Finding the right biological filter media is very important for the overall hygiene of your fish tank. It keeps the water clean and makes the environment safe for fishes and plants inside the tank.

If you are still confused about which biological filter media should you go with among the options mentioned in our list, here’s our recommendation.

You can never go wrong with the Fluval Biomax Filter Media. It is a perfect option in terms of price, quality, and efficiency.

Fluval is one of the oldest brands producing filter media and also has the highest rating amongst all its competitors. Additionally, in our tests we found it to be the fastest media to start denitrifying the water and balance the water chemistry.

5/5 - (12 votes)


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