Best Affordable Pond Filter Systems

Saltwater tanks are perfect for Lionfish, but if you want them to explore a natural environment, then you should think about creating a koi pond. Koi ponds are saltwater ponds, which are perfect for most of your saltwater fish. 

With the right tools, you could create a wonderfully natural environment for your Lionfish to thrive in, and today we are going to talk to you about one of the most important tools you’ll need to buy; the humble pond filter.

We know what you might be thinking, “but nature doesn’t have a filter, so why do I need one?”. The thing is, nature does have a filter. 

Normally, bodies of water, like lakes, still have a way to let water enter and leave the contained space. They do this by using streams to flow out of the confined area. They might even have springs that flow into the water as well. Otherwise, the water might come from the rains. 

It is very rare to find an utterly stagnant body of water, and if you were to find one, it wouldn’t be healthy for creatures to live in. That’s because these small, biological filters are nature's way to flush away the animal’s waste.

Some of these bodies of water also have animals that eat the waste and decay. Gross, but effective. 

For your home pond, you probably won't be able to create a spring to your nearest river, and you probably won't be able to convince nature's bin collectors to stick around your pond. So the next best thing is a filter system. 

We are going to dive into which type of filter you might want, how these filters keep your pond clean, and the secret of buying the right filtration system. 

If you want to jump straight to the good bit, we have compiled a list of 7 great and affordable pond filter systems at the bottom of this article. Jump on down to make your spending easy.

7 Best And Affordable Pond Filter Systems

So now you know all the details, you can buy the best pond filter system for your pond. We have gathered the best on the market, which are also reasonably priced, so if you're shopping on a budget, you can still purchase a fantastic filter. 


The TetraPond is the cheapest filter system on our list, but that doesn’t mean that it's terrible. The reason for its affordable price is its simplicity. This submersible flat box is perfect for anyone who is on a tight budget and has a small pond.

We would recommend it for a pond that has 250 gallons of water. But if you own a koi pond or a pond that receives a lot of sunlight, then you should only use it if your pond has around 125 gallons of water.

As this is a Submersible Filter System, all you need to do is place the filter into the pond and plug it in. The filter will do the rest. There is no need to fiddle around with pipes and pumps.

TetraPond has been running for over 50 years, so they know your pond needs. This system gives you the minimum requirement, so you know that your waters are clean and your wallet is safe.


  • Cheapest Filter System
  • Simple To Install
  • Good For Small Ponds


  • Not Powerful Enough For Large Ponds
  • Easy To Clogg


Pressure Filters with UV Clarifiers are the most expensive type of filter you can get. They can cost thousands and thousands of dollars. The SUN CPF-2500, however, is no way near that price range. Before you get too excited, we must let you know that it is the most expensive filter on our list, but still, it is no way near a thousand dollars.

The SUN CPF-2500 is just about cheap enough to still be considered an affordable purchase. But money isn’t everything. What can this baby do?

The SUN CPR-25000 has a self cleaning mechanism, so you don’t need to pull out the cleaning foams. It does this by dissolving a lot of the solid waste. 

The UV light fights against algae growth, which will make your pond maintenance that much easier. 

The SUN CRP-2500 also says it can handle 1,600 gallons of water. We know from before that 1,600 isn’t a realistic number, but 800 gallons or 400 gallons (depending on your pond) is still a high amount for the price ranges we are looking at.


  • Large Gallon Size
  • UV Clarifier
  • Easy to Maintain


  • Most Expensive on our list.


The Aquascape is the most strange looking pond filter on our list. Instead of being a box or a barrel shape, this filter looks like an 80s version of an alien spaceship. This flat design creates ceramic filtration rings, which are excellent for collecting and breeding good bacteria. 

The hose for this Submersible Filter is threaded, meaning that it has multiple connection sights. This is on purpose. The reason for the multi threading, is so that you can connect almost any pond pump to the adaptor.

If you use one of the pumps which come with the Aquascape, then there is a lot less maintenance included. That being said, the clips on the side of the flat surface area are for easy cleaning, so whichever pump you choose, maintenance won't be a challenging endeavor. 


  • Large Surface Area, So Less Bulky
  • Low Pump Maintenance
  • Multi Hose Adaptor


  • No Clear Gallon Size


This is another submerged filter for your pond, but the Pond Boss’s most significant feature is its sound reducing technology. 

None of the filters on our list are super loud, but if you worry about the level of noise your fish are subject to, then a supremely quiet filter is what you want. The quietness does come at the disadvantage of size. The Pond Boss has a bigger tank than most of the other filters, but this is to silence the overall noise level.

How the Pond Boss does this is through its multi layered foams. The first layer catches the more considerable debris, and the second layer collects dead algae. After that, the filter system has the plastic bio balls we discussed earlier. All of this technology muffles the overall sound, leaving a calming experience for you and your fish. 

Pound Boss says that their filter system can handle up to 500 gallons. So realistically, it can handle 250 gallons of a regular pond and 125 gallons of a koi or directly sunlit pond. 

The only real con of this filter is that it isn’t powerful enough for a waterfall feature. The Pond Boss does offer some great fountain heads, but if you wanted something more dramatic, then this filter might not be for you.


  • Quietest Filter
  • Multi Layered Foam For Multi Layered Cleaning
  • Submerged Filter


  • Not Powerful Enough For A Waterfall


The CNZ is known for its amazing suction power. The design is only a single unit of mechanics, but the simple outline is fixed with some clever technology that creates a 660 gallon per hour pumping system. This suction power alone means it's perfect for a Submerged Filter. 

The CNZ also has media filtration installed. It looks like a motherboard from far away, but in reality, the CNZ uses eco textile fabrics to line the side.

This media filter sieves out the sand and mud from the water and feeds it to the helpful bacteria. The healthy bacteria love to eat plant and fish waste, which is why we want to keep them happy in our pond landscapes.


  • Best Suction
  • Choice Between Media Filter Or Foam Filter
  • 3 Fountain Nozzles


  • Challenging To Install After Cleaning.


We haven’t discussed it much, but the big issue that most people have with Submersible Filters is the fact that you have to climb into the water to get the filter out when it’s time for a clean.

With the Aquagarden, you still need to climb in, but this is the only Submersible Filter that has handles. The handles lock into place when the filter is doing its job so they don’t disturb the fish, but when it comes to lifting it out of the water, you can easily grab the handles and pull the filter up.

You might not think that handles are that important, but imagine reaching into the pond, grabbing what you thought was a stable part of the filter, but it turns out to be the clip that holds the fish waste in. You pull it up, and all of the debris and grime which your filter has stored is now back in the pond.

With a handle, you know exactly where to place your hands, so you don’t have to deal with that kind of nonsense. 

The filter is made for 200 gallons, so more like 150 gallons for a koi pond or a pond in direct sunlight. 

The Aquagarden also has some fantastic features, which is why it is our top pick. It has the converted UV Clarifier light to kill off excess algae, it has three fountain heads to create different atmospheres for your garden, and it has waterproof LED lights to light up your water feature at night.

The only other filter which has a UV light and is a Submersible Filter is the Goplus which we will talk about last. Very few affordable filters that can go underwater have this fantastic technology, so to find one is a treasure. 


  • Handles For Easy Removal
  • UV Clarifier
  • 3 Fountain Heads
  • LED Lights
  • Submersible


  • No Cons


The energy-saving Goplus is the last filter on our list, and it is another submergible system. The Goplus uses four levels for its cleaning. The first one is a large coarse filter of foam to get rid of the big debris.

After that, there are three filter baskets, each of which has two extra filters in. This means that you will get top-notch water quality and will have to clean it out less often than the other filters.

A full filter needs more power to keep the filtration system going, but because the Goplus is ready for so much debris and grime, it will take longer to fill, and therefore needs less energy for the same amount of time as the other filters. 

Like some of the other filters on this list, the Goplus gives you three fountain heads to choose from to change up your aesthetic as the year goes by. It also has a UV Clarifier and an LED light to brighten up your water garden. 

The Goplus says they can clean up to 660 gallons of water, so in reality, it will be around 330 for a regular pond and 165 gallons for a koi pond or a sunlit pond.

The only negative for this filter is the customer support. Some customers have needed replacements for their filter, which is expected after a couple of years or even after a certain number of sales, but it seems that the customer support from Goplus isn’t as responsive or understanding as we might like.


  • UV Clarifier
  • 3 Fountain Heads
  • LED Lights
  • Submersible


  • Not The Best Customer Service

Best Affordable Pond Filter Systems Buying Guide

Why Are Pond Filters Necessary

The answer is simple. Waste. A natural body of water will have its own way to keep its inhabitants healthy, and if it failed to do so, the creatures would evacuate or die. Your pond doesn’t have any natural streams and probably doesn’t have the diversity of waste feeders that can clean up the mess. A pond filter does all this work instead, keeping your pond clean and healthy for your fish. 

Because your filter will be keeping everything clean, it will allow the water to look clear. This means the natural beauty of your fish and their landscape can be seen for the art that they are.

The Secret to Buying The Right Filtration System 

This sounds like we are about to bring out an ancient book of magic, but believe us when we say that there is a nack to buying filters. Most manufacturers advertise their filters based on the size of the pond they can successfully clean and regulate without the machine trying too hard and malfunctioning. They’ll say that they can do “X amount of gallons” to create a clean and healthy pond.

The thing is, for a filter to do this “X” amount, it would need all the conditions around it to be perfect. It would need low light, so the pond has fewer algae, it would need low plant life in the environment you’ve created for your fish, and it would need a low quantity of fish as well. Basically, this “X” amount is based on an empty pond in a factory.

This doesn’t mean the manufacturers are lying. It just means that the “X” amount probably isn’t going to be accurate for your pond. 

So how do you know the actual amount of gallons the filter can clean? The answer isn’t super simple. We have no idea what you have in your pond, so we can’t create an exact formula. Instead, there is a basic bit of math that can help you figure out the ball-park figure you’re really looking at.

Tip One:

Your pond probably isn’t empty. It likely has plant life that you want to keep alive, and you’ll clearly have fish in the water.  For this standard layout of a pond, the easiest thing to do is cut the gallon amount in half.

If the manufacturers say that the system can filter 2,000 gallons of water, then it can probably filter 1,000 gallons of an active pond.

Tip Two:

Tip one is for most people, but if your pond is hit with direct sunlight for all or most of the day, then you’ll need to cut that gallon amount again.

If you are creating a koi pond, then ignore tip one altogether. The salt in your pond will need extra filtration to avoid feeding the algae and harmful bacteria. 

Instead of cutting the gallons in half, you should cut it by three quarters. So if the manufacturers say that the system can filter 2,000 gallons of water, then it can probably filter 500 gallons of salty or max sunlit water. 

The Three Types of Pond Filters

External Gravity Return Pond Filters

This long-named pond filter does as it says on the label. It goes outside your pond and uses gravity to return the purified water to its home. 

The EGR filter is made of a plastic box and has foam filter pads on the inside. These capture the debris that comes through the filter. Once the container is filled with water, it flows through the box by using gravity.

If you are looking for an External Gravity Return Pond Filter, then we suggest buying one which uses coarse open cell foam. This is because they can catch large and small debris that comes through the pump.

Typically your filter won’t allow large debris because it might clog up the system, but sometimes you need the bigger bits filtered out too,

Because the EGRs have a foam to catch the debris, the filter itself is less likely to break from clogging. They are also one of the easiest to clean; all you have to do is remove the filter, clean or replace it and then reinsert it.

The biggest downfall of an External Gravity Return Pond Filter is that you have to hide it. Because the filter is outside of the pond, there is no natural way to keep it hidden. If you have bushes around your pond, then you could place the EGR there, otherwise, you might have to weigh the pros and cons of buying something to hide the EGR or having the EGR out in the open. 

Pressurized Pond Filters

Pressurized Pond Filters are often the most expensive. They are small barrels-like mechanisms that have a tight sealing lid. 

They work by forcing the water through to the filter via a pump. Because of the pump, this filter can be placed anywhere outside the pond, even below the water level. For the External Gravity Return Pond Filter to work, it had to be above the water level to allow the force of gravity to be activated, but seeing as the Pressurised Pond Filter has this pressurized pump system, you can place it anywhere you’d like. 

The most expensive Pressurised Pond Filters use a backwashing system that cleans the filter for you, so you don’t have to worry about maintenance, but most of them need you to open the sealed lid and wash the filter every now and then. 

Many Pressurised Filters include a UV Clarifier which we will talk about in more detail later. However, the addition of a UV Clarifier means that the rate of flow from the pump will drop by at least 40%. Keep this in mind when you are looking at the “gallon of water” formula we talked about earlier.

Submersible Pond Filters

Submersible Pond Filters are what most of us want to use. They are basic, easy to use, and can be left in the water to focus on filtration.

These filters have what is known as a “flow through” box. How it works is you find a flat spot in your pond, lay the filter under the water on that spot, and plug it in. 

These flow through boxes, like the External Gravity-Return Pond Filter, have foam pads that need to be cleaned. While the water is being sucked in, the filter pads collect the debris, but often the filter isn’t strong enough to clear up all the algae.

Some Submersible Filters try to get past this by including biological filtration balls. These bio balls float around your pond or even in the filter itself. Their job is to collect the bacteria and to keep them contained. Basically, the idea is that every now and then, you pick up the ball, clean it and plop it back into the water again. 

Because of the bio balls and the submersed filters, these systems force you into entering the water every time it needs to get cleaned, which means buying some waders.

The upside is that because they just need to be placed into the water, they are the easiest to install, and you don’t need to worry about a pump.

How UV Clarifiers Keep Your Pond Clean

We talked about UV Clarifiers briefly before, but let's get into some more detail. These clarifiers use up more energy which is why they drain the rate at which your filter can do its job. There is a good reason for this, though.

Algae can be a significant pest for your pond. Too much of it, and your beautiful water garden will be murky and dense. Algae is the grass of the underwater world, and it’s needed for so many things, but if you don’t keep an eye on it, the algae can take over your whole pond.

If you have a UV Clarifier, then this fantastic technology can massively reduce the algae. How it works is that the algae float past the UV light, and as it does so, the light penetrates the algae’s cells, forcing them to stop working. It does this through low levels of radiation, which is enough to kill a small cell in a plant but not enough to harm your fish. 

We would recommend that you have a UV Clarifier for a pond. Without it, the dead algae will naturally accumulate, creating a sludge that is terrible to look at and will cause harm to your fish.

The alternative is to climb into the pond and pull out any dead clumps regularly.


So now you have all the information about pond filters that you could ever need. Your Lionfish will be happy and excited to spend its days out in the exciting and most natural environment you can make for it.

Remember that Lionfish need koi ponds instead of regular ponds because they cannot handle freshwater environments. If you’re nervous about letting them into a pond at all, remember that they do best in saltwater tanks.