Best Pond Filter Media 2023 (Reviews & Comparison)

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Best Pond Filter Media 2023 (Top Media Compared)

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Why Select the Best Pond Filter Media Possible?

best filter media for koi ponds
Better filtration means clearer pond water and better water quality for fish.

Pond filtration is a complex process, but one that is vital for a healthy and balanced eco-system. It’s a process that can be refined through high quality media, and boosted with the addition of an extra stage of filtration, called chemical filtration, that doesn’t usually come with filters as standard. If you need to replace your old filter media, or maybe you’re just unhappy with your current filtration results, there is certainly ways to improve your filter’s efficiency by optimizing each step of the process.

Some of the benefits of selecting high quality filter media are:

  • Larger range of debris removal
  • More beneficial bacteria to remove harmful substances
  • Adding chemical filtration helps neutralize organic pollutants
  • Less filter cleaning required
  • Better water clearness and clarity
  • Helps create a more balanced ecosystem over time

Not all filter media is created equal, with some materials and designs being far better optimized than others.  What comes as standard with most filter purchases is very basic filter media which carries out its primary function, but is certainly not the best in its class. Luckily, replacing filter media is very simple, and usually just involves cutting mechanical (i.e, foam) media to size and adding the desired amount of bio-filtration (i.e., bio-balls) to your filter box.

2-Stage vs 3-Stage Filtration (Activated Carbon Benefits Explained)

activated carbon filter media
Activated carbon provides chemical removal and filtration for ponds.

All filters have a 2-stage filtration process which makes up the bulk of your water filtration system. The first stage is mechanical filtration which works to remove small and large debris from your water, and usually comes in the form of foam or sponge. This type of media is not optimized to hold beneficial bacteria, and is just designed to physically trap free-swimming debris which you can later remove when cleaning.

The second stage is biological filtration, which is designed to remove harmful substances, such as ammonia and nitrogen from fish waste, and convert it into harmless inorganic compounds. This process is called the Nitrogen Cycle, and requires a healthy colony of beneficial filter bacteria to function. These bacteria live within your biological filter media, and the best bio-media needs to be designed to support the maximum number of bacteria possible. The more bacteria that are present, the more harmful substances can be removed!

These are the most fundamental stages of filtration, but there is also a third and final filtration stage that doesn’t come with filters as standard. The third stage is called chemical filtration, with  ‘activated carbon‘ being most widely used as the chemical media of choice due to its efficiency. As the name suggests, the role of chemical filtration is to remove chemicals from your pond water. These chemicals, usually organic-based pollutants, are substances that your mechanical or biological filter media cannot remove without help. They include organic proteins, hormones, acids, and even outside chemicals such as pesticides, nicotine, and perfume. All these chemicals can build-up over time naturally from inside and outside your pond, and only with activated carbon can you fully remove them.

Check here for more information on activated carbon and our personal brand recommendations to help top-up your basic 2-stage pond filter system.

How often should you replace your filter media?

cleaning pond filter media
Mechanical media should be regularly cleaned with water to prevent damage and clogging.

High quality mechanical filter media is designed to last, so unless the media becomes torn or damaged, it does not necessarily need to be replaced. The same goes for biological filter media, such as bio-balls. Unless these become damaged, you do not have to replace them. If you keep up with cleaning and maintenance, most media will last a very long time.

With that said, if you feel your filter media is starting to degrade, it may be time to replace it with a new media. Mechanical filter media which is degrading in quality will become clogged faster and faster, even with sufficient cleaning. Bio-media that may need replacing is harder to identify, but if you notice an increase in waste (or smell) around your pond, it may be due to a loss of beneficial bacteria in your bio-media due to degrading performance of the material. You can replace the media, and also try topping up your beneficial bacteria levels with a concentrated beneficial bacteria supplement product.

In terms of chemical filtration and activated carbon, this does need to be replaced. Depending on the amount of fish, waste, and muck you have in your pond, we usually recommend replacing the carbon every 3-4 weeks for maximum benefits. After your pond becomes cleaner, you can drop this down to every 2 months and evaluate the results.

Choosing the Best Filter Media for Ponds (Considerations)

Mechanical Filter media – what to consider:

Filter media material
Mechanical filter media can be any material that removes suspended solid substances from your pond water, but often comes in the form of sponge, foam, brushes, matting, or polishing pads. There is no “best material” type here, as each material is designed to remove debris, and they all do this fairly well. With that said, we recommend foam for most filters as it’s flexible, readily available, and usually optimized in a range of sizes for maximum debris removal. Japanese style filter pads are also a good choice, but these usually have a more course and wiry structure. Most foam-style mechanical media is made from high quality polyurethane, which is a polymer with flexible and stable properties.  
Thickness of media
The thicker the mechanical media, the more time water and debris will need to pass through it. Thicker media provides better filtration and more debris removal, but it can also increase pressure buildup inside your filter. Thicker media may reduce water flow as well, depending on how course it is, which in turn can reduce oxygen levels in your pond. Even though all media is different, as a general guideline, we recommend media around 1-2 inches in thickness for most types. This should provide good filtration results, but not cause too many issues with water flow.
Number of layers
Having a minimum of 2 layers of mechanical media is optimal, with one being a course media for larger debris removal and one being much finer for small particle removal. Layering these with the larger on the bottom and the finer on top is preferred so the finer material doesn’t become immediately clogged. Pressurized filters will allow support for multiple layers of media, so you can experiment and see what sizes work best for your pond.

Biological Filter media – what to consider:

Specific Surface Area (SSA)
Biological filter media is made from a range of different materials, but all are optimized to provide maximum surface area for beneficial bacteria to grow. Material is not as important as the media’s overall specific surface area (SSA), as the higher the surface area, the more bacteria can grow and the better filtration you will have. If you have a media with a low surface area, you may need to add more of it to your filter if you have a lot of fish and waste buildup. It is usually easier to select a quality bio-media with a high surface area so you can use less and retain effective biological filtration. Good bio-media types include K1 rings, K3 rings, ceramic rings, or porous stone media.
Media Movement
Another thing to consider is whether or not the media is free-moving within your filter box. Some biological filter media, usually foam or matting, are completely static against your pump’s water flow. The problem with this is that dead bacteria begin to buildup slowly and cannot be removed from the media effectively without manual cleaning. The more dead bacteria that are present, the less biological filtration can take place.

Lighter, individual bio-media is often designed to be slightly buoyant and can move around your filter box as water flows through. This chaotic movement from your pump causes the media to move freely and self clean, removing dead bacteria so new bacteria can grow. Biological media such as K1 rings, k3 rings and some ceramic rings all provide movement and self cleaning to some extent.

Chemical Filter media – what to consider:

Always Choose Activated Carbon
Activated carbon is fantastic for neutralizing organic pollutants, and completely safe for your pond water and fish. When selecting a chemical filter media, make sure you’re choosing an activated carbon based product for maximum results and peace of mind. When deciding on a activated carbon based product, the most important point is the surface area of the carbon. The more surface area, or porosity, the more chemical filtration can take place! Some of the best carbon filter media is designed porous, allowing water to permeate through the surface and come into contact with the maximum amount of activated carbon.

Click below for our dedicated guide on activated carbon, as well as our personal product recommendations:

The Best Pond Filter Media Review 2023 (updated list)

Due to the different brands available between the US and UK markets, we’ve researched and divided our categories to provide both American and UK pond owners a review on some of the best pond filter media available, covering both mechanical and biological options.

Note: When adding new filter media to your pond, consider supplementing with concentrated beneficial bacteria to kick-start your bio-filtration and decrease harmful substance build up.

US - Best Pond Filter media US - Best Pond Filter media

Mechanical pond media

1) Matala Blue Filter Pad Review

A great range of mechanical filter media pads with varying degrees of  porosity. Matala’s blue filter pad is our favorite pick of the bunch, being made of high quality Thermo-Polypropylene Compounds (TPPC), in a curled design. The Matala blue filter pad provides 94% open space for water to pass through, and will have minimal effects on your filter pressure and flow. The material is very stiff, making it slightly harder to work with compared to classic filter foam, but providing fantastic durability in turn.

Unlike normal mechanical media which is optimized for debris removal, Matala’s range of media is also highly optimized for beneficial bacteria. There is a large surface area present within this media, so you will have a large increase in bacteria support alongside your normal bio-media. This means less harmful substances and more efficient waste removal!

The filter pads come in varies degrees of porosity, with the grey being the finest media and the black the most coarse. They can be combined and layered for maximum debris removal, or added individually depending on your needs. For most ponds, we feel the blue filter pad is the best middle-ground, providing both great debris removal, water flow, and room for beneficial bacteria to grow.

  • Type: Mechanical Media
  • Material: Polyurethane
  • Thickness: 1.5″
  • Pad Size: 39.5″ x 24″

Biological pond media

2) Matrix Bio Filter Media Review

A highly optimized biological filter media designed for maximum surface area and bacteria colonization. Matrix’s high capacity BioFiltration media is a naturally mined, chemically inert material that will not effect your pond’s pH levels. The material is highly porous, containing 160,000 cm2 of surface area per liter, making it exceptional for denitrifying bacteria to begin work removing ammonia and other harmful substances.

The media comes in the form of small stones, all with different shapes due to its organic nature. The stones are fairly light, and can be added to a filter media bag and placed within your filter, skimmer, or waterfall. We found that for ponds with larger filters, adding a bag made cleaning and maintenance much easier. If used in a much smaller filter, the media can be placed without a bag and it should remain in place.

Although slightly different to ceramic or plastic bio-media, Matrix is still a highly effective biological media, and we would recommend it for all pond types due to its amazing surface area and bacteria housing properties.

  • Type: Biological Media
  • Material: Processed Pumice
  • Placement: Filter box (Media bag recommended)

Biological pond media

3) Biological CerMedia MarinePure Media Review

Another great choice for highly optimized biological filter media is CerMedia MarinePure ceramic balls for ponds! Ceramic media is popular choice of biological filter media, but a problem is some brands are not porous enough to house enough beneficial bacteria to be effective. Luckily,  the MarinePure media range has a very high surface area index and porosity, giving the media a rough texture and allowing bacteria quick and easy colonization.

The media is designed for maximum beneficial bacteria, so would be ideal for fish ponds where decreasing ammonia and nitrogen are a primary concern. It can be added to any filter box, and does not require a specific brand filter to function. One box should be more than enough bio-media for most ponds, and the media will not need replacing for years if the filter and pond is maintained correctly.  The media is fairly light and moves around your filter box’s bio section with water flow, so is also self-cleaning and doesn’t require any maintenance. A great overall choice for most pond types looking for an effective bio-media with good surface area for bacteria.

  • Type: Biological Media
  • Material: Ceramic Balls
  • Placement: Filter box

Biological pond media

4) SpringFlo Bio Ribbon Media Review

An interesting and highly effective biological filter media choice is SpringFlo’s Bio Ribbon media. Unlike other biological media which typically comes in the form of several individual balls or rings, SpringFlo media contains one large plastic ribbon which is placed directly into the filter box. The ribbon is made from polypropylene and calcium carbonate, and is designed with an embossed diamond pattern which provides a high surface area for billions of beneficial bacteria to thrive.

One box of bio-media can threat up to 1,000 gallons of pond water effectively, and is placed directly into the biological media compartment of the filter box. Due to the shape and design of the media, it resists channeling, clogging, and does not decrease water flow from your pond pump. The media provides plenty of surface area for biological filtration, and due to its overlapping nature, is much better at trapping debris compared with other bio-media. Since this media is very difficult to clog, it may be beneficial for ponds with debris problems or heavy substance buildup.

Overall, an interesting type of biological pond media which provides fantastic bacteria housing conditions for ammonia reduction, whilst also providing secondary mechanical filtration due to its shape and design.

  • Type: Biological Media
  • Material: Polypropylene Ribbon
  • Placement: Filter box

UK - Best Pond Filter Media UK - Best Pond Filter Media

Mechanical media material

1)All Pond Solutions Filter Pad Review

A cost effective and highly versatile set of mechanical filter media foam providing filtration for a range of debris sizes. All Pond Solutions’ universal pond replacement filter foams are designed for use in any box filter, and come with 3 pads for fine and course filtration. The pads are placed on top of one another in your filter box, with the finest media being on the top and the coarse media being placed on the bottom. Make sure they’re placed in this order, as the finer media will quickly become clogged if placed incorrectly!

The media is around 1 inch thick, which is a good thickness for effective water filtration, and water flow should not be drastically affected. It comes in pre-cut sizes but can also be trimmed manually to fit almost any size or shape filter box.

Since this is not biological media, it does need to be cleaned to ensure maximum filtration benefits. The media is easy to clean, however, and can be reused so long as there are no tears or damage to the foam.

Overall, a simple but very effective 3-course mechanical media providing filtration against small and large debris which is suitable for all types of pond filters.

  •  Type: Mechanical Media
  • Material: Polyurethane foam
  • Thickness: 1″ approx
  • Pad Size: 17″x 11″, 25″ x 18″, 36″ x 24″ and 42″ x 21″

Biological pond media

2) Evolution Aqua K1 Bio Media Review

One of the best biological media for fish ponds is Evolution Aqua Kaldnes K1 bio-media. This media has been designed with a “moving bed” system in mind, meaning the media is constantly moving insider your filter. The K1 design is wheel shaped, slightly buoyant, and incredibly light, meaning your pond pump can provide constant media circulation. This constant movement allows self-cleaning to occur, with the old, dead bacteria being forced off the surface so new beneficial bacteria can continue to grow. This is a great choice of bio-media for pond owners who want the minimal amount of media cleaning and maintenance.

As well as its self cleaning properties, K1 has a large surface area index for maximum bacteria colonization. Each K1 media unit contains 800m² of total surface area for bacteria, providing a huge area for bacteria to break down harmful substances.

The media can be added directly to your filter box’s biological media section, and can also be added to a media bag if desired. Using a filter media bag will reduce the free movement of the media, however, so we only recommend this for non-pressurized filters where the media can slip past the mechanical foam.

Overall, one of the best and most optimized biological media types of ponds! Will provide great bio filtration for small, large, or koi ponds.

  • Type: Biological Media
  • Material: K1 Plastic
  • Placement: Filter box

Biological pond media

3) Blagdon Ceramic Bio-Media Review

A highly optimized ceramic ring bio-media from Blagdon, designed for heavy fish stocked ponds. This biological media is similar to Laguna’s, but is slightly larger in size. The media is very porous, and has a very large surface area for growing beneficial bacteria. Its shape is ridged in design, making the media more streamlined for better water flow and increasing its overall surface area index.

The ceramic rings are very high quality and easy to install in your biological section of our filter. They do not self clean as well as K1 rings, but still provide some movement so they don’t easily become clogged with dead bacteria. The media can be added to a filter media bag to make handling easier, but we recommend leaving them loose for maximum movement.

The material is chemically inert, and safe for both fish and plants. Due to the larger design of the rings, they would be beneficial for ponds with larger debris or for heavy fish stocked ponds. This media would be a great overall upgrade to basic bio-media and should provide very good filtration results.

  • Type: Biological Media
  • Material: Ceramic Rings
  • Placement: Filter box

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