Having a good pond pump is one thing, but unless you are looking to have a pond full of ugly green water, you are also going to need a good filtration system. At least if you are planning to have fish in the pond. The best pond filters will help keep the water reasonably clear and allow your fish to live a healthy life.
It can be a daunting task to choose the right filter for your pond. Therefore, this buying guide has been created for those who are not sure what filter to purchase.
How To Choose The Best Pond Filter?
As with anything else, there are certain factors, which should be considered when shopping for a new pond filter. We will go through the factors in the next couple of paragraphs. Remember that these are just general guidelines, and may not apply to all the different scenarios.
Filter Type
Most modern filtration systems will have a combined functionality of a UV filter, mechanical and biological filter. The UV filter will help with keeping the green water at bay, while the biological filter and helpful bacteria will take care of breaking down toxins produced by the fish or physical waste such as excess fish food. Keep in mind the best filtration system needs be running 24/7, otherwise, the helpful bacteria will start dying due to lack of oxygen. The mechanical filter will catch larger solids from the water and needs to be cleaned periodically to prevent clogging.
We can also divide filters based on the way they are connected to the pond.
Gravity return filter – Probably the most popular filtration system which utilizes a submersible pond pump which pumps the water to the filter from which the water passes via small waterfall or stream back to the pond.
Pressure filter – These sealed filters are usually hidden in a small chamber in close proximity of the pond. Again, the water is pumped directly into the filter by the pond pump and leaves the filter under pressure via an outlet back into the pond. A setup like this is great for smaller ponds because of its flexibility and easy installation. A more powerful pump is needed for this type of filtration.
Gravity feed filter – These complex filter systems mostly used in large ponds and will usually require expert help to install.
Filter Size
Just like with pond pumps, having the appropriate to the size of your pond is absolutely crucial. One of the things to remember is that you can never over filter the water. Therefore, getting a larger filter than necessary is not a mistake. On the contrary, it will leave you some space for possible future pond modifications.
On the other hand, by choosing a small filter for a large pond will prove to be a bad idea because the filter will not be able to properly clean all the water.
Now the important question should arise – how to choose the right size? The clear majority of good pond filters are rated for certain maximum pond volume in either liters or gallons. All you need to do is to calculate the approximate volume of your pond and then choose a filter based on the calculated number. It is not a bad idea to go oversize especially if you are planning to have lots of fish in the pond – typically more than 100 fish per 1000 gallons of volume.
Best 5 Pressurized and Gravity Fed Pond Filters
The next couple of paragraphs will be dedicated to some of the best rated pressurized pond filters for 2021 based mainly on customer reviews and ratings. Please note that the products are listed without any specific order in place. So, without further ado, let’s start with the first one.
Goplus Pond Pressure Bio Filter 4000GAL W/ 13W UV Sterilizer
This pressurized filter is recommended for ponds up to 2500 gallons with a normal fish load or 1500 gallons with a heavy fish load. Its flow rate is rated for 4000 GPH and the filter also contains UV purifier which some of the competing filters do not have. With the help of the UV purifier, your pond will be algae free within a couple of days and your fish will enjoy the clear water. A good pairing would be this filter and for example a 1200 GPH pond pump.
Features at glance
- Flow rate: 4000 GPH
- Fitted with UVC ultraviolet purifier
- UV Power: 13 W
- Filter capacity: 25 liters
Pros
- Good value for money
- Good for small to medium ponds
- Comes packed with hose adapters
Cons
- Can be difficult to find some replacement parts in case something goes wrong
- Instructions can be confusing
Customer ratings – This was the best rated pressurized filter available online at the time the article was being written. Many of the customers considered the model to be good value for the money with its low price (at least compared to the competition).
TetraPond Bio-Active Pressure Filter with UV Clarifier
The next in line is a pressurized filter by the popular TetraPond company. While it is not as cheap as the first model we talked about, you will be buying from a trusted company with lots of experience. The filter comes in three different versions based on the pond size rating. Just like you would expect, the bigger the filter, the higher the price. The smallest model is rated for ponds up to 1500 gallons. Other variants are rated for 2500 and 4000 gallons. For most people, the basic variant is likely good enough.
With the mechanical, biological and UV filtration, the filter will be able to clear your water quickly and efficiently.
Features at glance
- Rated for 1500, 2500 or 4000-gallon ponds depending on the selected variant
- Integrated UV tube
- Mechanical and biological filtration
- Backflush valve for easier cleaning
Pros
- Very effective cleaning
- Features a backflush valve for easier filter media cleaning
- Great customer service
Cons
- High price
- Some of the customers reported water leaking into the UV light tube
Customer ratings – The filter system received a positive response from the users with some of them claiming it to be the best-pressurized filter on the market. There were some minor problems reported by the customers but most of them have been handled well by the customer service.
Grech CPF-2500 Pond Bio Pressure Filter
This is a rather small filter meant for ponds up to 1600 gallons. That is if you only have a decorative pond. In case you have a pond with fish, the manufacturer recommends this model only for ponds up to 900 gallons. Thanks to its small size, it is incredibly easy to hide the filter from sight making it much less distracting to the eye.
The filter provides both biological and mechanical filtration and it is also equipped with a 13W UV lamp. Together the filtration units will take care of both floating particles and microorganisms.
Features at glance
- Rated for 1600 gallon ponds without fish or 900-gallon ponds with fish
- Equipped with 13W UV clarifier
- Packed with inlet and outlet adapters
Pros
- Good value for money
- Simple cleaning system
Cons
- Rated only for smaller ponds
Customer ratings – The filter belongs to the best-selling pressurized filters for small ponds and has received quite positive reviews from the buyers. One of the reviewers stated that his 1000 gallon pond went from 3” visibility to be able to clearly see the bottom in mere 4 days. Some of the reviewers however mentioned leaking problems with their units.
Laguna Pressure Flo-Clean 2100
This pressurized filter is meant for ponds up to 2100 gallons. One of the features that set it apart from other filters is the patent-pending cleaning system, which lets you clean the whole foam filter surface without the need of opening the filter itself.
Another neat thing is Laguna’s quick click fit system which allows you to quickly connect hoses to the filter’s body.
Features at glance
- Rated for 2100 gallon ponds
- Mechanical and biological filtration
- Canister volume – 8.2 gallons
Pros
- Easy cleaning
- Cleaning indicator
Cons
- No UV lamp
- Relatively high price
Customer ratings – There were not many customer reviews available at the time of writing, but those that were available, were very positive.
OASE BioSmart 5000 Pond Filter
Oase is another very popular company when it comes to pond related accessories and devices. This filter is rated for 5000-gallon ponds, which is enough for most customers. On the other hand, if you have a larger pond, Oase also offers a 10 000 gallon version of this filter. Please keep in mind, those values are rated for fish-free ponds.
Some of the interesting user-friendly features of the filter are a built-in cleaning mechanism, which spares you from having to manually unclog or remove the filter foams, cleaning indicator, or sludge drain.
For the filter to work effectively, a pond pump rated at 1 200 to 2 000 gph is needed.
Features at glance
- Rated for 5 000 gallon ponds
- Provides mechanical and biological filtration
- Cleaning indicator
- Temperature gauge
Pros
- Good aeration
- Reasonable price
- Easy to clean
Cons
- Instructions could be better
Customer ratings – Customer reviews of this filter have been generally very positive and it is considered to be one of the best gravity fed pond filters on the market. One of the customers noted this filter did a much better job in cleaning his pond than a pressurized filter he had owned before that. On the other hand, another customer has reported missing parts in the package.
Biological Water Filtration In Detail
This term refers to a set of biochemical processes that occur naturally in water under natural conditions. This is a very simple process in which useful bacteria in the filter remove harmful substances from the water that endanger the life of aquatic animals and promote uncontrolled growth of algae and cyanobacteria.
Maximum efficiency of nitrification processes is achieved by providing a slow flow of water through a large amount of filter material with bacteria with sufficient oxygen saturation.
For effective filtration, a sufficiently large volume of filter material with the largest surface area of the material is needed. The larger the area, the more useful bacteria will reside in the filter and the more harmful substance will they “eat”. Filter size is critical, so the filter is never too large.
The efficiency of biological filtration is greatly affected by the pre-filtering, ie. mechanical filtration. Its purpose is to remove scattered dirt and small particles from the water. This allows not only to maintain maximum water transparency but also to remove organic impurities before they start to decompose. If this stage of filtration is missing, the biological part of the filter is rapidly clogged and thus the power is reduced. The most commonly used mechanical filters include: vortex, slit filter, brush chamber. Regular cleaning of the pre-filter guarantees the quality of the entire filtration process.
Frequently asked questions
Do all ponds need a filter? – The answer is no. If you are not planning to have a lot of fish in the pond or are planning to build a natural pond, then you will not necessarily need a number but you will need a large amount of plants to achieve natural nitrogen cycle balance.
How do I clean the filter? – This is highly dependent on the filter type and model you purchase. The filter should be packed with instructions on how to clean it properly. Unless the filter has self-cleaning functionality, you will have to clean it regularly.
Conclusion
There you have it, this is the end of today’s best pond filters buying guide, which you had hopefully found at least a little bit helpful. In case of any questions arising that haven’t been answered in the article, please do not hesitate to use the comment section below to ask them. Or if you wish to, you can use the Contact page to get in contact with me. Looking forward to seeing you again with another article in the future.