Best Pond Filter 2023 (Reviews & Comparison)

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Best Pond Filters for Koi, Goldfish, and Garden Ponds 2023 (Updated)

Selecting a pond filter may appear to be an easy choice, but there are a number of factors to take into account to ensure you get the best water filtration possible. Not all pond filters are made equal, so in this article we’ll break down the information to help you filter out the top pond filters on the market!

US Pond Owner? We recommend... US Pond Owner? We recommend...
UK Pond Owner? We recommend... UK Pond Owner? We recommend...


Does my Pond Need a Filtration System?

how to filter koi ponds
Filters remove debris, break down harmful substances, and help improve water quality in fish ponds.

A pond filter has the very important role of housing beneficial pond bacteria which are necessary to the breakdown of harsh substances, as well as filtering out free-swimming debris from pond water. Ponds without sufficient beneficial bacteria populations may have dangerously high ammonia and nitrite levels, caused mainly from decomposing organic matter on the pond floor and fish waste.

The bacteria populations that build up in your pond filter will slowly break down these substances during the filtration process, greatly reducing the levels in your pond. Ammonia is broken down into nitrites, and this in turn into nitrates, which plants and algae will readily absorb – a process called the nitrogen cycle.

As well as this, pond filters also help remove free swimming organic matter, debris, and small particles which can contribute to muddy water. These things become trapped between the different levels of filter media and will be removed when cleaned. Anything that passes from the water through your pond pump will eventually arrive at your filter, and it’s your filters primary job to catch the unwanted debris and stop it re-entering your pond system.

Filters are necessary for pond owners whose ponds are easily filled with debris. Ponds which are close to trees, bushes, or foliage, are all prone to build up of floating debris which eventually sinks and begins to decompose as bottom sludge. They’re also essential for ponds with koi or goldfish, as the beneficial bacteria inside your filter box will be the primary process for breaking down harmful substances from the decomposition of organic waste. Without a means of water filtration, ammonia and nitrate levels would slowly increase over time and become dangerous to both pond fish and wildlife.

Should I purchase a filter with UVC?

how to get rid of algae with a UV clarifier
UV Clarifiers are a safe and effective way to remove green algae, and come included in most modern filter systems.

It has become more common for filters to come with added Ultra Violet Clarifiers in recent times to help combat both green water (algae) and harmful free-swimming bacteria. A pond filter with UVC will both help filter water and destroy algae during the filtration process. A pond filter with added UVC is a better choice in most cases to a regular pond filter, unless you already have a separate UVC unit.

With that said, even if you have a separate UVC unit, you can still purchase a pond filter with added UVC as this will only increase the rate at which both algae particles and harmful bacteria are removed, and should not adversely affect your pond’s ecosystem.

Note: A pond filter is designed to remove larger debris and particles from a pond’s water, as well as house beneficial bacteria, but it sometimes cannot remove very fine particles that may be the cause of dirty water. To catch smaller particles, a much finer filter media can be added to the filter to supplement the filtration process until water clarity improves. Check our article here for more information on removing fine particles and tannins which can cause dirty pond water.

Water Filtration – What is actually happening?

As the water passes from your pond pump to the filter, there are different layers of filtration taking place. The best quality pond filters will make the most of each type of filtration to maximize results, lower the amount of cleaning required, and enhance overall water quality.

“Media” is a term used to describe anything that provides a filtration function within the filter.

Biological Filter Media
This is the primary pond filter media which is present in every single pond filter, and is essentially any filter media that can house beneficial bacteria growth. This aerobic (oxygen using) bacteria will work inside the filter media to break down harmful substances, such as ammonia and nitrites.

The most basic of media includes a simple sponge material which doubles as a mechanical filter, housing bacteria for biological filtration and providing mechanical filtration itself. As well as common sponge media, ceramic rings, plastic rings, or bio balls are also great biological filter media. When cleaning a pond filter, you need to be careful not to over clean the media where the bacteria lives. Using fresh water to clean media housing bacteria can quickly kill your population, and cause problems with your pond’s balance. Check our guide here for help with cleaning bio-media and filtration systems without damaging the media.

Mechanical Filter Media
Mechanical pond filter media is essentially anything that will remove organic particles from pond water, including small twigs, leaves, and debris. As the pond water passes through this media, particles will become trapped, and will later need to be removed when the filter is cleaned. Unlike biological filtration, where the bacteria will break down particles, a mechanical media will simply trap the debris and will require manual removal every few weeks. Although beneficial bacteria will readily colonize this media, the surface area is not usually optimized for bacteria growth, so you will still need biological media alongside.
Carbon Filter Media
While carbon-based media doesn’t often come as standard in filters, it is very useful for removing heavier chemicals and organic substances that biological and mechanical media cannot remove. The most common carbon media is activated carbon, which is very effective at removing a range of heavy organic pollutants, including chlorine, pesticides, colors, and fish pheromones. Adding activated carbon to your filter system provides a third stage of water filtration, improving water quality and reducing substances that can lead to sick and unhealthy fish. 

Optimizing Water Filtration for Maximum Benefits

Just because a filter may come with everything you need to get started, doesn’t mean there aren’t still ways to help make filtration more efficient! Supplementing with beneficial bacteria can help reduce ammonia, and cleaning your mechanical media correctly will ensure maximum debris is removed. Even feeding your fish a better quality food can help with filtration by reducing the amount of water and harmful substances in the pond water.

Below are some useful articles which cover ways to improve filtration, water clarity, and water quality:

Different Types of Pond Filter Systems

1) Box Filter (Non-pressurized, no UVC)

Box filters are the simplest form of pond water filtration

A basic box filter is the simplest form of pond filter available. This type of filter is usually small, containing just the pond filter media and input/output options. This type of filter will work well to keep your pond water healthy for fish keeping, but it will NOT prevent green water (algae) build up. Regular box filters are not pressurized and the pond filter outlet should always be kept above the water line. This is the most basic kind of filter available, and has mostly been replaced with pressurized filter options or non-pressurized box filters with UV clarifiers.

Cost effective for small ponds
No additional wiring needed
Easy to clean and maintain
Will not remove green water (algae)
Can become easily clogged
Needs to be kept at ground level

2) Box Filter with UVC (Non-pressurized)

Box filters both filter and clarify water
Hozelock Filter with UVC

A very popular choice of pond filter, providing both pond filtration and water clarifying benefits. This pond filter is similar to the basic box filter above, but comes with a UV light bulb which works to remove green water (algae) during the filtration process. This type of pond filter should function almost identically in terms of filtration as a regular box filter, but the added UVC means green water will not be a problem. Since the filter is not pressurized, however, it cannot be placed below the water line and is less easy to hide.

Removes green water via UVC (algae)
Cost effective duo solution
Great for water clarity
Will not reduce water flow
Requires electricity to power UVC
Needs to be kept at ground level

3) Pressurized Box Pond Filter (With/Without UVC)

Pressurized box water filters are able to be placed anywhere in the pond and are easily hidden
Laguna Clear Flo Pressurized Filter

Similar to the normal box pond filters, but with a pressurized structure. This means the filter can be placed almost anywhere in your garden and easily hidden. The filter can be even placed below the water level, so you’re able to partially bury this kind of filter out of sight. Pressurized pond filters also can include an added UVC bulb to combat green water as well as providing basic pond filtration benefits.

A final benefit of a pressurised pond filter is due to its increased pressure. This allows a finer mechanical filter media to be obtained, which can further improve water clarity. Many newer models also come with a dedicated discharge function and semi-automatic cleaning system, which allows you to clean mechanical media without having to open the filter box.

A downside of pressurized filters is that they greatly reduce water flow inside the filter, so will need a pump with sufficient strength to provide good circulation. They’re also not recommended to be coupled with water features, as they will significantly increase the head height requirement of your pump. We always recommend a dedicated pump for a pressurized filtration system for best results.

Can be positioned above or below ground level
Allows for denser filtration media
Versatile and cost effective
Great for water clarity
Reduces water flow from pump
Requires electricity to power UVC (If chosen)

What type of filter do we recommend?
 A pressurized filter with UVC has the most versatility, as it comes with 2-stage filtration, algae control,  and allows installation above or below the water line (buried). Having the UV clarifier combined with the filter is a convenient option as it helps save both money and space if you don’t already have a separate unit. However, the addition of a UVC bulb means you’ll need to provide electricity to the filter, so you’ll want to ensure you have access to a mains socket at the site of installation.

If you intend to run your filter alongside a large water feature, such as fountain or waterfall, we recommend a non-pressurized filter so water lift height is not significantly reduced. Pressurized filters greatly reduce water flow inside the box, and this will, in turn, significantly increase the amount of head height required to power a water feature. In these instances, we would usually recommend running a separate pump to the water feature, and keeping your main filtration system on a dedicated circuit, as this provides easier maintenance, better head heights, and more efficient filtration,

As a final note before we move on to the recommendations, you’ll need to make sure your filter is compatible with your pumps strength. So if your pond pump is rated at 1000 gallons per hour, you’ll need to make sure the filter will work effectively under this pressure. Check your pond pumps flow rating against the filters specification! 

The Best Pond Filter Reviews 2023 (Top Models Compared)

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 the best pond filters available. We have listed below our best pond filter picks available to both the US and UK market.

Have a large Koi Pond?  Check our separate article here for filtration systems designed for heavy stocked fish ponds and much larger pond systems.

US - Best Pond Filters 2022 US - Best Pond Filters 2022
Our Top Pick

1) The Laguna Clear Flo Pressurized Filter filters water and breaks down debris using bacteriaLaguna Clear Flo Pressurized Filter Review

Our top pond filter choice is the Laguna Clear Flow range of pressurized filters with added UV clarifiers. This highly versatile pond filter comes with two types of filtration, biological and mechanical, as well as a handy UVC for algae removal. Its biological filtration process takes place through 3 pieces of media foam as well as highly optimized “Bio-Lava Rock” gravel – which are essentially optimized balls inside the filter for beneficial bacteria to quickly colonize and flourish. During regular filtration, the different sizes of media foam easily trap dirt and debris, whereas the bio-rocks provide ample surface exposure for bacteria to break down a large amount of waste substances from the water.

The most interesting and useful aspect of this particular filter is the innovative back-flush system that helps with filter cleaning and maintenance. When this system is used, water is reversed inside the filter with water jets creating a whirlpool effect in the filtration chamber. Whilst the debris circulating is loosened, the dirty water is ejected from a flush value which can be angled into your garden for easy removal. Make sure the back flush cap is secure even when not using the function or you’ll have leakage! Also, we recommend after bacteria colonies have had time to establish (around 5-6 weeks) to perform a back flush clean before water flow becomes visibly reduced. This will make cleaning and future maintenance much easier and prevent beneficial bacteria dying off from lack of oxygen content.

As well as its filtration and cleaning options, the filter range comes with a 13w UVC light to help with algae removal. This strength of UV should be sufficient in controlling algae in all but the largest of ponds, and should also help with free-swimming harmful bacteria control.

Since this filter is pressurized, and due to its back flush system, you will need to ensure you have a pond pump strong enough for it to function efficiently. For the smallest filter, the 2000 Clear Flow, a pump around 500-800 GPH is recommended. For the largest filter, the Clear Flo 14000, a pump between 2500-3000 is recommended for best operation.

Overall, a reliable and economical pressurized filter, the Laguna Clear Flow range provides great 2-stage water filtration and an effective means for bacteria colonization through it’s unique lava rock bio-media.  The back flush cleaning system is a useful addition, but you’ll need to make sure your pond pump is up to the job for the best results.

Great filtration process
Useful flush system
Strong UV light
3 year warranty
Requires a strong pump for best results
  • Pressurized: Yes
  • Pond sizes: Suitable for ponds between 500 and 5000 gallons (model dependent)
  • Type of filtration: Biological and mechanical
  • UVC Strength: 13w
  • Outlet Size: Fits 1- 1/2 inch  (ID) tubing
  • Dimensions: 13.6 x 14.3 x 22.6 inches
  • Warranty: 3 Years

2)Jebao CBF Pressurized Filter Review

Our next US pond filter choice comes in the form of Jebao’s cost effective CBF series pressurized bio filters, which are a new product range replacing the older CF-10 models. Jebao has already created a reputation for itself by providing extremely cheap filter equipment while still retaining high standards of quality. This new CBF filter range works to remedy problems with the older design by adding new features and better quality materials, whilst still retaining the same low asking price.

The same as other filters here, the Jebao comes with a 2-stage filtration system, providing both biological and mechanical filtration layers. The water is filtered through a large porous sponge media which surrounds the central filter chamber, collecting debris as water swirls and passes through it.  At the base of the filter is a large section for bio-media, which Jebao has provided in the form of optimized bio-rings. These needed to be added manually to the bottom of the filter (around 1/3 of the bag will do), and will work to reduce harmful waste substances as beneficial bacteria start to colonize.

Unlike the older models which felt a bit cramped in design, the intake, outtake, and discharge valve here are all nicely spaced apart, allowing for much easier installation. The back-flush system has also been improved, providing stronger flushing of media and a durable handle which needs to be “pumped”, instead of turned – which, in our opinion, is much easier for cleaning.

The filter is pressurized, so can be submerged or buried easily, and comes with different strength UVC lights as standard to eliminate green water. The smaller 1000 gallon models comes with a 13w bulb, and the largest 4000 gallon model a 36w bulb, making it suitable for larger stocked fish ponds. In terms of durability, the filter is a large step-up from the older CF-10 filters which felt very light and fragile, but still lacks some of the premium build quality in more expensive branded options. This can been seen in the somewhat flimsy handle, stiff back-flush knob to divert water to the discharge hose, and single layer of mechanical media foam.

Overall, an extremely cost effective pond filter, the Jebao CBF series provides a decent filtration system with a strong UV clarification options for pond owner on a budget. Best suited for smaller ponds, low fish stocks, or those looking to find the best balance between quality and price.

Good filtration process
Cheap for pressurized filter
Strong UV lights
2 year warranty
Build quality could be better
  • Pressurized: Yes
  • Pond sizes: Suitable for ponds between 1000 and 4000 gallons (2 models)
  • Type of filtration: Biological and mechanical
  • UVC Strength: 13 Watts (1000 model),  36 Watts (4000 model)
  • Outlet Size: Fits 1″, 3/4″, 1/2” tubing
  • Dimensions: 10 x 10 x 16 inches
  • Warranty: 2 Years

3) The oase biosmart filter is pressurized but doesn't reduce water flow as much as other pressurized filtersOase BioSmart Filter Review

A great non-pressurized pond filter choice is Oase’s BioSmart filter series. These filters feature a streamlined “flow through” design, meaning water flow is not reduced as much as pressurized options.

The filtration process is a standard two-stage, with highly optimized foam media acting as both a biological and mechanical filter media. Included are 4 layers of different sized mechanical foam, which have been designed to house a large quantity of beneficial bacteria. They have also been designed to catch a range of different debris, including both fine and large particles.

The media itself is very easy to clean and maintain thanks to a built-in cleaning mechanism that prevents the need to physically remove the media foam. The filter also comes with a cleaning indicator light so you know when the media becomes clogged  – which is very useful.

As well as the cleaning indicator, the filter comes with a temperature gauge for monitoring water temperature, and a handy sludge drainage outlet to remove buildup under the media. All these things combined makes the Oase BioSmart a very user friendly filter that would suit new pond owners, or pond owners who want easier filter maintenance.

In terms of UV options, the filter comes with a 9w UV light at the front of the inlet. Water drawn from your pump will first be clarified and algae removed before entering the filtration stage. This is the most efficient design to ensure dead algae doesn’t re-enter the pond water.

The filter is very easy to set up, but needs to be placed at ground level as the box is not pressurized. It will also require connection to your mains socket for the UV light to function. The only real complaint with the filter is the slightly fragile outtake design which tends to come loose occasionally. If you have a strong pump, you may need to add some elbow fittings to tighten the outlet to prevent it coming loose.

Overall, a very user-friendly non-pressurized filter option that provides great biological and mechanical filtration. Would suit both large ponds or smaller fish stocked ponds, and is one of the easiest filter systems we’ve reviewed to clean and maintain.

Great filtration process
Very easy to clean and maintain
Temperature gauge and sludge drain
Strong UV light
Outlet design is a bit flimsy
  • Pressurized: No
  • Pond sizes: Suitable for ponds of 5,000 gallons or 10,000 gallons
  • Type of filtration: Biological and mechanical
  • UVC Strength: 9w
  • Outlet Size: Fits 3/4″, 1″, 1.25″ and 1.5″ tubing
  • Dimensions: 23 x 16.1 x 19.1 inches
  • Warranty: 2 Years

UK - Best Pond Filters 2022 UK - Best Pond Filters 2022
Our Top Pick

1) The all pond solutions pressurized filter system comes in many sizes for all different pondsAll Pond Solutions Pressurized Filter Review

A favorite of ours, the All Pond Solutions PFC Pressurized filter with UVC is one the best UK pond filters we’ve reviewed. Their huge range of different pond filter models provide a solution for the smallest of ponds to the very largest of ponds. All models come with a powerful and reliable UVC system to eliminate green water,  and provide an easy “spin-clean” system so you don’t need to disassemble the filter when it becomes clogged.

One of the reasons we love this filter is its ease of use and the options available! Since having a pressurized filter can hugely diminish the flow from your pump and cause problems with any water features you have on the same loop, you can choose to purchase a kit which includes tubing and a separate pump, eliminating this concern.

As well as this, the easy spin-clean system allows you to manually rotate and squeeze the sponge media and then remove the dirty water from a discharge outlet. You would rarely need to disassemble this filter as the cleaning system works incredibly well. When cleaning is eventually required, a useful float indicator will rise on the top of the unit informing you to perform a spin-clean – no need to guess or wait for low water flow.

The actual filtration process is broken down into both mechanical and biological filtration, with each model providing a different number of layers of media. In all models, water passes first through medium-fine filtration media to remove larger debris, and then through activated “bio-balls” which have been optimized to house millions of bacteria. These bacteria will break down the smallest of organic debris and harmful substances before the water moves on to the UVC clarifier in which algae is eliminated.

Overall, the All Pond Solutions PFC pond filter is one of the best pond filters you can buy on the UK market. The filters come in a huge range of models, supporting ponds of all sizes, and have an extensive filtration process for healthy water. The filters come with UVC as standard to eliminate algae from the water, and provide a useful spin-clean system and discharge outlet so there is no need to disassemble the filter itself.

Great filtration process
Good cleaning/maintenance options
Strong UV light
2 year warranty
Requires strong pump for best results
  • Pressurized: Yes
  • Pond sizes: Suitable for ponds from 5,000L to 50,000L (depending on model)
  • Type of filtration: Biological and mechanical
  • UVC Strength: 11 – 55 Watts (depending on model)
  • Outlet Size: Fits 3/4″, 1″, 1-1/4″ and 1-1/2″ tubing
  • Dimensions: 310 x 310 x 405 (5000 model) – 600 x 600 x 815 (50,000 model)
  • Warranty: 2 Years

2) The hozelock ecopower filter is a great choice for those who don't need a pressurized filterHozelock EcoPower Filter Review

A non-pressurized box filter with UVC, the Hozelock Ecopower pond filter is a good option for pond owners who do not need a pressured structure. As this is a normal box filter, the filter cannot be submerged and needs to stand upright. The filter can be buried, however, up to the lid level making it easier to hide than other box filters.

2-stage filtration is included in the form of plastic bio-rings for bacteria to colonize and 2 layers of medium-fine sponge for mechanical filtration. Unlike the pressurized filters we have recommended, there is no easy clean function but the filter has a small sludge discharge outlet on the bottom for easy drainage and sludge removal. Since the structure is not pressurized, you can easily remove the filter media and clean the filter box by hand. Depending on the debris levels in your pond water, this may need to be done every few weeks.

The UVC light is powerful enough to clear all green water in your pond within a week or two, and runs reliably for long periods. The inlet supports a range of different tubing sizes for convenience, and Hozelock provides kits which includes pumps if you want to run the filter in a new loop from your water features. A downside is that only 2 layers of mechanical media are present, so finer debris in the water more easily passes through. A third layer of finer media would have been beneficial, but it still functions well to clean pond water.

Overall, a simple and easy to use non-pressurized box filter with UVC that will help remove debris and algae from your pond water. The filter is very easy to clean and setup, but with only 2 layers of sponge media for filtration may not be suitable for extremely dirty water.

Good filtration process
Easy to clean and maintain
Strong UV light
2 year warranty
Only 2 layers of mechanical media
  • Pressurized: No
  • Pond sizes: Suitable for ponds from 4000L, 6000L, 10,000L (depending on model)
  • Type of filtration: Biological and mechanical
  • UVC Strength: 6 – 16 Watts (depending on model)
  • Outlet Size: Fits 3/4″, 1″, 1-1/4″ and 1-1/2″ tubing
  • Dimensions: 385x 405 x 400
  • Warranty: 2 Years


3 thoughts on “Best Pond Filter 2023 (Reviews & Comparison)”

  1. I have been using the 25000lt AllPondSolutions PFC Pressurized filter with UVC for 2 years now on a 20000lt pond system. water quality and clarity has been fantastic throughout the time of the system running.

  2. If I get the pressurized filter with UV and an aeration device, will it work fine together? Because when I was reading about the filters, it said it needs to be hooked up to a pump. But in your article I read that pumps are for oxygenation only but aeration is both oxygenation and water flow. So I am confused. My pond is about 3.5 feet depth and 19×24 in dimention. Thank you


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