Last Updated on April 23, 2023 by Coral Realm

The aquarium filter media is a vital cog in the workings of your fish tank, working non-stop behind the scenes to keep your water, and therefore your fish and plant life, healthy and clean. If you don’t have the right filter media your water will become cloudy and dirty, and your aquarium fish will suffer.

It can be very confusing to choose the right media for your fish tank as there a multitude of different options which you can choose from. Hopefully this guide will help in your search for the best aquarium filter media for you.


Best Aquarium Filter Media

Best Aquarium Filter Media

The following table contains the 6 best filter media available today and their main features. This will allow you to easily see and contrast the filter media with one another. 

We will go into detailed reviews of each of these aquarium filter medias further on in the article.

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Aquarium Filter Media Categories

There are three different types of filter media. Used together they form the most effective way to utilize the filter for the filtration of your tank’s water. These types of media are mechanical, chemical, and biological. A filter which has all three of these filtration stages is said to have triple stage filtration. Both HOB filters and canister filters use mechanical, chemical, and biological filter media to clean aquarium water.


Mechanical media is the front line of defense in your filter as it eliminates food, waste, and other larger pieces of dirt and debris visible in your tank. 

This type of media is any kind of barrier that prevents this unwanted gunk from re-entering your aquarium while the water carries on flowing through the rest of the filter. This barrier can be a mesh or net, or any other physical barrier. 


The most commonly used chemical media in filtration systems are activated carbon and zeolite. As the name suggests, these remove the chemicals that build up in your aquarium water, such as ammonia, that will otherwise be dangerous to your fish and plant life. 


Biological media is the most nifty of the lot, as it works in a similar fashion to human gut bacteria. You provide a suitable place for beneficial bacteria to grow, such as through bio-rings, and this bacteria will then proliferate through feeding on the nitrates in the water, removing this harmful substance from your tank. 

You don’t have to do much, as bacteria should grow on the objects you provide without aid. Bacteria love porous media with a lot of surface area, and this will also maximize the effectiveness of the biological media by ensuring the greatest amount of water is cleaned as possible.

Best Aquarium Filter Media Reviews 

Best Aquarium Filter Media Reviews

1) Aqua Flo Aquarium Filter Media 

Aqua Flo Aquarium Filter Media
  • Over 30 years of proven customer satisfaction with our green filter product.
  • No chemicals used in production! Safe for all fresh or saltwater fish, tanks & ponds.
  • Easy to cut with scissors to any size needed.
  • Proudly Made in the USA by an American Company

Aqua Flo is a very respected brand who have been supplying happy customers with good quality aquarium products for many years.

The company has a policy of not using any chemicals in the manufacture of their products, which means that they are all perfectly safe for use in all freshwater and saltwater aquariums, tanks, or ponds that you have own.

This aquarium filter media is comprised of two distinct layers; a coarse layer to catch any larger particles and debris, and a finer layer to grab the smaller particles that fall through the first layer.

This filter media comes as a large 12 x 6 feet roll which you can easily cut with scissors to any size you need. So you don’t need to worry about it fitting your tank, and as it is a large roll it lasts a good while.

2) Aquarium Filter Pad – Premium True Dual Density Aquarium Filter Media Roll

Aquarium Filter Pad – Premium True Dual Density Aquarium Filter Media Roll
  • 2 LAYERS EQUALS CLEAR WATER: This unique 2 Layers in 1 filter media pad combines a typical aquarium filter pad with a water polishing pad. The top...
  • SEE THE DIFFERENCE: When you clean this true dual density filter pad, see how much more debris it traps compared to other aquarium media pads. Your...
  • CUT TO FIT: FilterFirst filter media aquarium pads can easily be cut to fit your filter. Our unique poly filter pad is PERFECT FOR FRESHWATER, REEF...
  • SAFE AND DURABLE: Our aquarium filter floss pad is constructed of durable polyester fibers making it strong and durable enough to be rinsed and reused...
  • TIP: Place our FilterFirst dual action polyfilter pad in flowing water with the open filter floss weave side up to trap coarse and fine particles....

This filter media pad from Aquatic Experts has a dual density design composed of two layers to capture both large and small particles. The thick layer captures debris before it clogs the tightly woven thin pad so it can last longer in your tank.

The thick loosely woven layer stops larger particles such as leftover food and decaying plants, and the tightly woven thin layer removes fine debris such as detritus.

No dyes or chemicals are used in the production, so nothing harmful will leak into your tank and harm your fish. The roll of filter media can be cut into any size you need, so can fit any number of different filter types and sizes.

3) MarineLand Black Diamond Media Activated Carbon

MarineLand Diamond Media Premium Activated Carbon, Blacks & Grays, 40-Ounce (PA0373)
  • FOR CHEMICAL aquarium FILTRATION Black Diamond Premium Activated Carbon removes odors discoloration and impurities for clear sparkling aquarium water
  • SPECIALLY FORMULATED Composed of heat-activated bituminous coal-based carbon
  • FOR ALL FILTERS Ideal for use in all aquarium filters
  • MARINELAND FILTRATION PRODUCTS Count on Marineland brand for the most reliable technically advanced aquariums and accessories on the market
  • Included Components: Trusted Marineland Carbon Specifically sized to be more efficient Premium Black Diamond works as much as twice as fast as the competition

Marineland Black Diamond Media Premium Activated Carbon removes more discoloration, odors and impurities compared to the next leading competitor according to a 2015 University study. Therefore you will get unrivaled cleaning ability using this aquarium media. 

It is composed of heat-activated, bituminous coal-based carbon, which gives your tank the boost it needs. It has rave reviews, and everyone who uses this product say their aquarium has never been clearer.

This aquarium filter media is ideal for all aquarium filters and is specifically sized to be more efficient. It comes in small peddles, which increases the surface area so it works quicker and more efficiently cleaning your tank.

4) MarineLand Ammonia Neutralizing Zeolite Blend Aquarium Carbon Media

Marineland Diamond Blend 50 Ounces, Ammonia-Neutralizing Zeolite And Carbon, aquarium Filter Media
  • REMOVES AMMONIA Blend of Black Diamond Premium Activated Carbon and Zeolite removes toxic ammonia and impurities
  • FOR FRESHWATER Ideal for all freshwater aquariums and ponds
  • TEST FREQUENTLY Test water regularly for ammonia levels and add Diamond Blend as instructed
  • MARINELAND FILTRATION PRODUCTS Count on Marineland brand for the most reliable technically advanced aquariums and accessories on the market
  • Age range description: All Ranges

This is a blend of activated carbon and zeolite which clears your tank and removes impurities. The carbon removes odors, discolorations, medications, chemicals, and heavy metals from your aquarium while the zeolite removes toxic ammonia and chloramines.

Zeolite can only be used in freshwater aquariums however. So if you have a freshwater tank the double action of carbon and zeolite is very effective.

Thus filter media will work very well in your freshwater tank to remove dissolved organic compounds which are harmful to your tank if not filtered out.

5) Fluval External Power Filter Pre-Filter Media

Fluval Pre-Filter Media, Mechanical Filter Media for Aquariums, Ceramic Rings, 26.45 oz., A1470
  • Mechanical filter media prevents finer filter media from clogging
  • Solid ceramic rings trap large and medium solid particles
  • Works to prevent clogging of finer filter modules
  • Helps reduce the replacement frequency of filter media
  • Ideal for medium and coarse filtration in freshwater and saltwater aquariums

This aquarium filter media by Fluval are designed to capture solid waste before they reach other media. This prevents the finer filters in your system becoming clogged early, thereby extending their live and saves you money having to replace them. 

The media consists of ceramic rings which are inert so don’t mess with your aquarium’s chemistry. They trap large and medium solid particles before they clog the finer sieves of the modules above. The shape of the hollow rings allows for diversified water flow, and beneficial bacteria will establish themselves on the surface of the rings, further removing ammonia and nitrite from the water.

These rings are also reusable, simply rinse off the waste they have captured and pop them back into the filter.

6) CNZ Aquarium Filter Media Kits

CNZ® Aquarium Filter Media Kits (Double Pack) - Activated Carbon, bio Ball, Ceramic Ring
  • Removes odor, colors, organic pollutants, Helps reduce and control ammonia and nitrate
  • For freshwater or marine environments
  • Extremely porous ceramic media for efficient biological filtration.
  • provides superior filtration and beneficial bio-filtration growth
  • increase dissolved oxygen levels

This aquarium filter media kit from CNZ is a great option, as it contains everything you’ll need to get your filter up, running, and cleaning your aquarium.

It comes complete with bio balls, which are engineered to be perfect for colonies of bacteria to grow and provide biological media. Activated carbon is also included which filters out ammonia, nitrates, and other substances.

Ceramic rings are included as well for mechanical filtration, filtering out larger particles of detritus and food debris. Beneficial bacteria will also grow on the extra space these rings offer. 

These three different filter media will provide your aquarium with good quality filtration, keeping your tank clean and healthy. 

7) Seachem Matrix Bio Media

This filtration media by Seachem works brilliantly in the filter to provide excellent biological filtration. The media can be used in any aquarium; freshwater, saltwater, or reef, due to the fact that it is inert and won’t change the pH balance of the water.

Matrix media is very porous and is designed to provide exceptional bio filtration for removal of harmful compounds such as ammonia and nitrates. This design means that the media provides a far greater surface area for bacterial colonization and growth than plastic ball media. One litre of matrix provides over 170 square foot of surface, which can equate to over 40 litres of typical plastic media!

It is recommended that one litre of Seachem Matrix bio media is used for every 100 gallons of water. The media is large enough that a media bag is not necessary to use it in most filters. A filter bag is in general a good idea though, and we always recommended using one.

As this media is organic and made from naturally mined substances the size, shape, and coloration of each can vary. The results will be the same though. Just ensure to rinse the media thoroughly to remove and dust that may have accumulated. 

How should you layer your aquarium filter media?

The proper way to layer the aquarium filter media seems like common sense once you’ve had it explained to you, but if you don’t have the info it can seem confusing.

First up is the mechanical media. Mechanical media should be the first line of defense, as it filters out large particles of dirt and detritus. It stops these larger particles from clogging the later stages of the filter. Mechanical media also enables easy cleaning of the filter as the particles collect on the top.

Biological media should be the next in line, but if you have a dual-purpose media put that in before. Dual purpose encompasses things like ceramic rings which act as both mechanical and biological media, as they filter large particles from the water and also provide a structure for beneficial bacteria to grow. 

Biological media are after the dual-purpose media. Biological media utilizes beneficial bacteria which feed on the chemicals within the water and clean your tank. It is important that it is cleaned and changed regularly so it doesn’t get clogged with debris. The biological media layer relies on the flow of water to bring the food and nutrients the bacteria need to survive.

The last layer is the chemical media. Once the water has passed through the mechanical and biological medias the chemical media removes whatever is left dissolved in the water. If it is placed before the biological media there is a risk that the bacteria won’t survive, and the chemical media may degrade quicker than normal. So having the chemical media as the last line makes sense to enable each layer to function efficiently.

As you can see in the image below, the first layer the water meets is the mechanical filter media, in this case filter pads. The next layer underneath are bio balls; the biological media. Here bacteria will grow which will remove harmful compounds. The final media is the chemical media. In this case carbon is being used in mesh bags.

How to layer aquarium filter media

How often should you clean your aquarium filter media?

The filter is the most important piece of kit in your aquarium. It filters the water and keeps your fish and plants fit and healthy. If the filter isn’t functioning properly ammonia, nitrates, and chloramines can build to dangerous levels.

Larger tanks generally require cleaning less frequently than smaller aquariums, and the more fish you have then the filter will require cleaning more frequently. After all you are mostly trying to filter out the stuff the fish make!

It is important to test your aquarium regularly, we suggest weekly, using testing strips. These strips will give you the levels of nitrate, ammonia, pH, and other information. When there is a change in the levels of these important chemicals on your tank it is time to change out and clean your aquarium filter media. 

A good trick as well is to keep an eye on the flow of water out of the filter. If it starts to look slow it is most likely due to the filter clogging up, so give it a clean. Normally the aquarium filter media needs cleaning around once a month but keep an eye on the strip tests and go from there. No sense in cleaning it out if it doesn’t need it!

Mechanical and biological media such as ceramic rings and bio balls can be cleaned using water. However never use tap water, use tank water. Fill a bucket with water from the tank and clean them in there, shaking out all the gunk. 

The chlorine in tap water can damage the aquarium filter media, and can also harm the fish when placed back into the filter. It will also harm the bacteria growing on the biological and dual action media, which will take time to regrow. As you should clean the media in the tank water, the easiest way to clean the filter is when you change the water and clean the aquarium, since you’ll already have a bucket ready. 

How often should you replace the aquarium filter media?

Mechanical and biological media don’t need to be changed often. These filter media types can be used until they have basically fallen apart. Because mechanical media traps larger pieces of detritus and gunk, it doesn’t need to be perfectly new out of the box to still work. You should regularly check the filter. The mechanical media needs to be changed if you find that pieces of debris are getting to the biological or chemical media which should’ve been stopped.

When the biological media needs replacing, only change about a third at a time, and pick out the most badly damaged ones. As beneficial bacteria grow on the biological media you need to keep some old media in there. This is so the colonies of bacteria which have grown on the old media can grow into newly introduced media. The functionality will be greatly decreased if you replace all the media at once; the bacteria will need to grow again, which can take a while.

Chemical media such as activated carbon should be replaced about once every three weeks. This will ensure that the media functions correctly and maintains your water quality. Carbon degrades over time as it filters out and reacts with the chemicals in your aquarium, so it needs replacing regularly. If you see the water becoming discolored, change the chemical media and it should fix the issue.


For your filter to be at full function, you need all three of the aquarium filter media types; mechanical, biological, and chemical. All the aquarium filter media listed here are great and work well. They each can argue they are the best filter media of their type.

However if you want something which covers all aspects then the CNZ aquarium filter media is the way to go as you get all three media in the one package.

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