Having the best Koi pond filter is essential to help you keep your pond safe and clean. Koi fish are one of the most unique and beautiful species of fish that are easy to breed in ponds. They reproduce quickly, eat a lot, and are very active. But this also means that they produce large amounts of waste, which can be challenging to clean if you don’t have the right filter.

Considering the large size, selecting the best filter out of hundreds of options available can be difficult. So to help you out, we tested out the most popular options and have curated a shortlist to help you find the best filter for your pond.

Comparison Chart

Name Maximum Flow Rate (in GPH) Maximum Pond Size Compatibility (in gallons) Size (in inches)

OASE BioSmart 10000 Pond Filter

3600 10000 31.1 x 23.2 x 17.7

AST BBF-XS1000 FIlter

600 1000

35H x 16 Dia.

(Cylindrical Filter)

SUN CPF Grech Pond Bio Pressure Filter


1600 Approx. 1500 12 x 16 x 12

CNZ Pond Filter System[/easyazon_link]

660 Approx. 500 15 x 14 x 6

[easyazon_link identifier="B01CPX5JSM" locale="US" tag="badmant-20"]Aquagarden Submersible Water Filter

369 600 14.4 x 15.6 x 7

Handpicked Reviews of the Best Koi Pond Filters

Let’s get straight into our list of the best Koi pond filtration systems:

1. OASE BioSmart 10000 Pond Filter


  • Ideal for up to 10,000-gallon ponds
  • High filtration surface area
  • Easy cleaning
  • Built-in cleaning indicator


  • Quite large and heavy

The OASE BioSmart 10000 Pond Filter is a robust and sturdy device built for heavy-duty use, making it great for ponds with many Koi. It has an impressive flow rate of up to 3600 GPH allowing it to efficiently clean up waste and debris from Koi ponds up to 10,000-gallons in capacity.

Along with this heavy flow rate, this filter also has an exceptional cleaning system ideally suited for Koi ponds. The system allows the filter media to have more contact with water, which substantially boosts the biological filtration capacity. Also, the device is designed so that water flows directly through the media, making it much more efficient at catching smaller waste particles in your pond.

A common concern people have with most large filters is that they are challenging to use and maintain. It is not the case with the OASE BioSmart Filter. It offers various convenient features such as cleaning handles and a sludge drain that make it just as easy to use as any other filter.

The inbuilt cleaning handles are located on the top of the filter and allow for convenient and easy maintenance. That is because they can be removed without much effort enabling easy access for replacing the filter media. Moreover, this device uses unique sludge drains to keep larger waste out of the internal parts. So, you won’t have to worry about the filter getting clogged up by your pond’s debris.

Along with this, you’ll never miss out on maintenance as the filter’s built-in cleaning indicator notifies you whenever the media needs replacement. Moreover, there is also a water temperature display which is very useful to maintain the pond temperatures for the delicate Koi fish. All these convenient features make it easy to use this filter and maintain your fish pond.


The OASE BioSmart 10000 Pond Filter is a heavy-duty device perfect for larger Koi ponds up to 10,000-gallons in capacity. It has a robust flow rate combined with an advanced filtration system that can keep all kinds of waste and debris away from your pond. The device is also straightforward to maintain thanks to its cleaning handles, sludge drain, indicators, and more, making it suitable for beginners.

2. AST BBF-XS1000 FIlter


  • Various sizing options
  • Easy maintenance
  • Powerful bio-filtration
  • Sturdy build quality


  • Slightly expensive

If you are looking for a sturdy device that will last you for many years, the AST BBF-XS1000 FIlter is an ideal option for you. It has an impressive build quality and doesn’t need filter media replacements, so this filter will continue working efficiently even without regular maintenance. Also, this filter works perfectly with most ponds up to 1000-gallons in capacity.

One thing we liked about this filter is that, unlike most filters, it does not utilize any moving internal parts. It makes it much less likely to suffer from any mechanical malfunctions while also reducing the amount of heat it produces.

In terms of filtration, this device is excellent for keeping Koi ponds crystal clear thanks to its unique bead filtration system. This system uses various tiny beads to block debris, and it offers superior water clarification. AST claims that this system can block 100% of particles larger than 50 microns in size, which is much better than most competition.

In addition to this, the filter also uses a biofilm to improve biological filtration capacity. It works by breaking down toxic waste and making water safe for your fish and plants. It is beneficial for Koi ponds as it can efficiently neutralize the large amounts of ammonia produced by Koi fish.


The AST Bubble Bead Filter is an ideal choice if you are looking for a well-built and trustworthy device for your Koi pond. Thanks to the lack of moving parts, it is very reliable and doesn’t require any filter media replacements, making it very easy to maintain. Moreover, this filter also offers high-quality filtration with a unique bead system that is great for keeping toxic Koi ponds clean.

3. SUN CPF Grech Pond Bio Pressure Filter


  • Can cope with higher water flows
  • Quick and easy cleaning system
  • Promotes aerobic bacteria growth

UV technology


  • Non-submersible

If you have trouble keeping your pond clean, the SUN CPF Grech Pond Bio Pressure Filter is an option you should consider. It has an impressive 1600 GPH flow rate and uses various filtration stages to give you an efficient and all-around cleaning procedure. So, you won’t have any trouble keeping your pond hygienic with this filter.

The filter uses a multi-stage system with separate biological and mechanical filter chambers. It allows for more efficient filtration of solid as well as dissolved waste in your pond water. Moreover, the biological chamber is designed to promote the growth of beneficial aerobic bacteria, which is great at removing toxic ammonia and nitrite from the water.

However, unlike most filters on the market, the SUN CPF Grech Pressure Filter also uses a powerful integrated UV-C light unit for filtration. As UV-C light effectively kills harmful bacteria and algae in the water, it gives the filtration capacity a powerful boost. Combined with the rest of the system, this filter is perfect for Koi ponds, and you won’t have to worry about your water quality again.

The filter is also an ideal choice for beginners as it has a simple installation and maintenance. It comes with all connections on the top so you can easily attach all the needed pipes. The filter also has an intuitive, quick-handle cleaning system making maintenance clean and quick.


The SUN CPF Grech Pond Bio Pressure Filter is a powerful device that is efficient at keeping large ponds clean. It uses biological and mechanical filtration along with a powerful UV-C light system to keep your fish pond hygienic. The device is also easy to install and maintain, making it an excellent choice for beginners.

4. CNZ Pond Filter System


  • UV-C filtration light
  • Multiple filter media baskets
  • Fully submersible
  • Fountain or waterfall output options


  • Confusing maintenance

The CNZ Pond Filter System is a great all-in-one device suitable for beginners to Koi ponds. It is lighter than most options on the market but still offers a decent 660 GPH flow rate ideal for most medium-sized Koi ponds. Also, the filter has a compact design, so you won’t have any trouble moving it around or placing it in your pond.

You can also make full use of the compact shape as CNZ has made this filter fully submersible. It makes it easy to hide and suitable for Koi habitats with heavy decor as you can preserve your pond’s natural look. Along with making it easier to hide, the filter’s ability to submerge also makes it easier to use with the various added accessories.

These fountain heads are probably our favorite part about this filter, and CNZ has added three unique options. So, you can choose between a sizable misty spray or a more enclosed one with the lotus fountainhead/ It also comes with a splitter so that you can divert water into a waterfall for more smooth and gradual filtration. Whichever option you go for, the filter has an adjustable water flow so that you can customize it to your liking.

This device is a step ahead of the rest for water filtration with a great all-around system for cleaning. It uses a large coarse filter combined with three filter media baskets to provide an efficient cleaning process. An added benefit is that the filter media baskets can be used with various filter media to adjust them according to your requirements.

Along with this, the CNZ Pond Filter System also comes with a built-in 13w UV-C lamp. It is great at killing unwanted microorganisms such as bacteria and viruses in your pond water. However, with all these filter media, maintenance can be pretty expensive with this device.


If you are a beginner looking for an all-in-one pond filter for Koi, the CNZ Pond Filter System is a great option for you.  It has a light and compact design, making it easy to use while also offering an impressive 660 GPH output. Moreover, the filter uses a complex filtration system combined with UV lighting to keep your water clean. However, maintaining this filter is quite expensive.

5. Aquagarden Submersible Water Filter


  • Lightweight
  • Multiple water output options
  • Inbuilt LED spotlight
  • Safety switch for UV lighting


  • Only suitable for up to 600-gallon ponds

The Aquagarden Submersible Water Filter is an excellent option if you are looking for small Koi pond filters. The device itself is only one pound in weight and is small enough to fit into your pond without running the decor and aesthetic. That being said, it is only suitable for tanks that are up to 600-gallons capacity.

People have a common concern with smaller filters that they may not have as many features as other larger ones. However, this is not the case with the Aquagarden submersible filter, as it is jam-packed with aesthetic and filtration features such as LED and UV lighting.

When it comes to maintaining your pond’s beauty, this is one of the best devices on our list. The filter comes with four unique fountain output nozzles, so you can choose to have the water flowing out in a large spray or in a pretty tulip design to suit your theme. Also, the filters inbuilt LED spotlight lights up your pond and the fountain making it very enjoyable to watch at night.

Along with keeping your pond looking great from the outside, this filter also has a great three-stage filtration system that will keep the water clean. The system works by initially catching large dirt and algae in a coarse foam filter. A medium-sized filter then catches smaller particles until the water finally passes through a polymer wool pad. It polishes the water and removes any remaining impurities leaving your pond with clear water.


If you have a Koi pond that lacks free space, the Aquagarden Submersible Water Filter is an option you should check out. It is a small and compact device, so you can easily fit it into your pond and hide it behind larger plants. Also, the filter has a fountain water outlet with a built-in LED light, so while it may be small, it will surely give a significant boost to your tank’s beauty.

Things To Consider While Choosing a Koi Pond Filter System

Here’s a list of some things you should consider when looking for a Koi pond filter system:

– Water Flow Rate

The total output or water flow rate is one of the most critical factors you should look at when buying a Koi pond filter. That is because using a filter with a low flow rate or filtration capacity in a large pond can lead to increased toxicity and harm your flora and fauna. It is especially true for Koi habitats as these fish produce lots of waste and need the water to be regularly filtered.

A good rule of thumb you can follow to find the correct output is to multiply your tank’s volume by 1.5. Doing this will give you the GPH or minimum output needed to keep your tank clean and healthy for any pets. So, if you have a 1,000-gallon pond, according to this rule, you should buy a filter with a flow rate of approximately 1,500GPH.

– Aesthetic Features

Koi ponds are often known for their beauty, whether due to the spectacular inhabitant Koi fish or the landscaping of the pond itself. Many filters available in the market offer aesthetic features such as fountain outlets or lighting systems to promote the look of your pond.

So, if you are trying to landscape and build a beautiful pond, try to look for filters with features that will benefit your pond’s look and theme. For example, if you have a pond with external lighting, buying a filter with an inbuilt LED will improve the overall lighting from inside the water.

– Filtration System

Koi fish are known to be very beautiful and majestic. However, they are also some of the most challenging fish to maintain. That is because they have a tendency to root up their pond’s ground and are also known to produce a lot of waste for their size.

Because of this fact, it is vital to purchase a filter with an efficient filtration system with the suitable stages/media needed to clean waste and larger debris. Preferably, for larger ponds, we suggest that you find a filter with powerful mechanical, biological, as well as chemical filtration.

– Size and Shape

Unlike aquarium filters that have easy-to-fit HOB or corner-shaped designs, pond filters are usually much bulkier. Along with this, many pond filters have fountain/spray water outlets requiring them to be centrally located in your pond and also close to the surface.

Due to this, it can sometimes be challenging to find a suitable filter, especially if you have a smaller pond. Thus, make sure to check out the dimensions as well as the shape of a filter to see if it will fit where you want it to before making a purchase.

– Running Temperature

A common problem with heavy-duty power filters is that they produce a lot of heat while running continuously. It is caused by the various moving parts and can cause many issues for Koi ponds in the long run.

If you live in a warmer area and maintaining a cool temperature is a problem, try looking for filters with better heat management systems. Also, many options available have unique designs without internal moving parts that can heavily reduce the heat produced, making them great for all types of Koi ponds.


Let’s discuss a few frequently asked questions related to Koi pond filtering systems:

1. How Big Should a Koi Pond Filter Be?

While there is no set guideline for how small or large a Koi pond filter should be, it is ideal to have a filter that can completely clean your tank’s water at least two times an hour. So, this means that if you have a 1000 gallon pond, it would be best to look for a filter with an output of 500 GPH.

2. Are Pressure Filters OK for Koi Ponds?

Yes, pressure filters work fine with most Koi ponds and are usually simple to set up and maintain. That being said, other types like gravity filters will also work fine, and it is up to you to see which one suits your pond the best.

3. Are Koi Ponds High Maintenance?

Koi fish are known to be one of the dirtiest and high-maintenance species of fish to own. It is because they produce a lot of waste for their size and are also known to disturb your pond’s surface, bringing substrate and debris into the water.

4. How Many Koi Can Be in a 3000 Gallon Pond?

If you have a proper filtration system set up in your Koi pond, we would suggest that you keep one Koi fish per 250-gallons of water. So, for a 3000-gallon pond, you should be able to keep a maximum of 12 Koi, but it would probably be better to keep less than 10 to avoid any problems.

5. How Often Should You Change the Water in a Koi Pond?

If you have a smaller pond below 5000-gallons in capacity, we suggest a 10-15% water change per week. On the other hand, ponds larger than 5000-gallons should be sufficient with a 5-10% water change weekly.

6. Should a Koi Pond Be in Sun or Shade?

While Koi ponds can be kept in either sun or shade, building your pond in a shaded area is advisable. While full sun works, having your pond in the shade will reduce sunlight, slowing algae growth. Also, the shade will help regulate temperature during hotter seasons, wherein direct sunlight can be harmful.


We hope you found a suitable filter that matches your preferences and fits your budget. However, if you are still confused and want our final recommendations, we are here to help. Even though all the options on our list are top-tier pond filters for Koi, there is one that stands out. After thoroughly testing all the options, we recommend the OASE BioSmart 10000 Pond Filter as the best Koi pond filter.

The device is excellent for even larger ponds up to 10000-gallons in capacity and offers an impressive 3600 GPH output. It also comes with various features such as a cleaning indicator and anti-clog drains, making it easy for beginners.

That being said, we hope that this list helped you find the perfect Koi pond filter for your pond!

5/5 - (14 votes)


Please enter your comment!
Please enter your name here