If you are keeping fish, you need a filtrations system to maintain water quality for the fish to thrive (and even survive as well) and that is a fact. It doesn’t matter whether you have a tiny aquarium or a large pond in your backyard, filters are a must. But when it comes to ponds, things get a bit complicated. And if it extends beyond that and you add fish to the equation, then ponds aren’t just needed, they become compulsory.
Especially when it comes to fish such as koi, then you must ensure that they have a proper filtration system put in place for them so that they can live in the pond happily with the quality of water maintained for them. In this piece, we will get in the depth of filters for ponds with koi fish in them and what are the best and safe practices to ensure your fish remain happy and the water quality remains healthy.
After doing countless hours of research, our expert has selected this best koi pond filter. So, pick one according to your need after reading our experts review of that specific filter.
Why You Need a Koi Pond Filter
It goes without saying that koi fish, albeit loved by all, is notoriously messy. Similar to an indoor aquarium and irrespective of the type of Koi pond (whether natural or constructed with cement or liners), the pond needs cleaning which is fundamentally important to the health of the fish, hence the importance of a proper filtration system can never be undermined.
The practice of keeping Koi fish is gaining traction globally and people are becoming ken on opting for the best filtration system that they can possibly afford as koi themselves have a big effect on the water quality. With them, it is not quite easy to keep the pond neat and clean.
The filter makes sure that the water is cleaned of any debris along with the mess (bioload) made by the fish. Besides this, with the required water conditions met adequately, your koi fish will grow much more quickly and stay healthy.
Some people believe they don’t need a filter when they start out with koi, but in time, they discover that they can’t make do without having a proper filtration system put in place. The bioload will keep increasing on a yearly basis (or as fish grow) depending upon the number of koi fish you have in the pond and at some point, people who initially believed they are good without a filter to start to regret their mistake. Don’t be one of those people and make preparations from the start.
Type of Koi Pond Filter
Koi pond filters are essential as they help in removing dirt, algae, debris, and bioload from the pond and help to maintain a proper balance of the water in the pond. They do it by adding beneficial bacteria to the pond from a matured filter that helps regulate the conditions to be better suited for the koi fish. Although there are many different types of filters that you can choose from, the two main types best suited for ponds with koi fish in them include:
Just as the name suggests, a pressurized filter is pressurized; this means that the filter is basically a sealed tight container and the water is ‘pushed’ through it. The main application of pressure filter is for small to medium-sized ponds. They are quite easy to install but consume additional horsepower pumps in comparison to non-pressurized filters.
Categorized as mechanical filters, pressurized filters work by forcing water through a filtration sponge that is used for the collection of debris and particles and offers more convenience and flexibility to the pond owners in comparison to other types of filters. Moreover, since they operate on the principle of pressure, they can be stored anywhere, or more specifically, concealed underground or hidden behind a waterfall system to mask their presence and prevent it from ruining the scenic landscape of your koi pond.
Pressurized pond filters are often equipped with many other features such as UV sterilizer or others that help in effective removal of algae particles from the pond water. Surely you must be aware of what a filtration sponge is, so some water filters are equipped with a function called ‘backflush’ that allows for easy and fast cleaning of that filter sponge in the pressurized water filter without causing much nuisance. Pressure water filters can also be deployed in combination with pond skimmers so the skimmers can handle the smaller pond debris while the filter handles the rest.
As we have mentioned, pressurized filters are listed under the category of mechanical filters so they lack the essential functionality of biological filters.
Pro tip: If you are going with a pressurized pond filter, we recommend getting one with a higher pond volume rating than the actual volume of your pond. Additionally, if you use a pre-filter before the pump, it will do a lot of mechanical filtering for you and your actual pump will remain much cleaner, hence the need for backflushing will decline.
Non pressurized filters are…well, non-pressurized. The lid on the top isn’t air-tight and atmospheric pressure comes and goes as it, please. Gravity is the main catalyst which allows for the water to exit the filter and flow to the pond, and some of the non-pressurized pumps are built to completely operate on this principle (gravity fed) so there are no pimps involved. But just as we said ‘some’, most of the non-pressurized filters require pumps to be used in order for them to complete the cycle.
The plumbing for non-pressurized filters is designed such that it proceeds away from the filter in a downward configuration. This requires for the whole system (filtration system) to be placed over the surface and at some elevation so that the water actually exits the plumbing at the end.
Currently, two main types of non-pressurized filters (gravity return) are used commonly. The first one makes use of simple plumbing exit ports that are connected to the returning plumbing pipe. The second type has a spillway return (waterfall weir) from which water spills in the form of a waterfall into the headwater area. Both the types can be either of either up-flow or down-flow configuration which depends upon the position of the baffle inside the filter. Whereas the name (up or downflow) signifies the direction in which water flows through the filter and varies as per the preference of the users.
Another type of non-pressurized filters is submersible, which is also the highest maintenance type. They are deployed inside the pond and are typically used for beginner ponds. They are placed on the bed of the pond and completely submerged along with the attached pump. The side of the filter that houses the filtration media is where the pump is connected so the pump gets bogged time and time over again. It is under the pressure of the pump that unfiltered water is drawn in through the media.
Although non-pressurized filters may take a bit more time in comparison to pressurized filters for setting up the whole system with limited location possibilities due to their dependence on the gravity return that requires them to be placed at a higher location. But they offer the following benefits:
- They don’t require high horsepower pumps like pressurized filters as the system doesn’t require the water to be forced through the filter.
- The filter can easily be checked repeatedly and evaluated whether it needs to be cleaned or not.
- As the media is exposed to the atmosphere, in case of a power outage, the depletion of dissolved oxygen is relatively slower in comparison to pressurized filter.
Top 7 Best Koi Pond Filters
Now we move our attention towards some of the best and most suited filters for Koi ponds. Not only they have been tried and tested, but serve their intended purpose so well that they are a worth recommendation.
Number 1: OASE BioSmart 5000 Pond Filter
An innovative and efficient flow-through filter that offers maximum oxygenation and undertakes both, mechanical and biological filtration. With smart sludge drain, it is easy to remove any coarse debris with no need to remove or manually unclog the filter foams. It is designed to be nature-friendly technology that has a positive effect on the wildlife in the pond and is suitable for ponds with a capacity of around 10,000 gallons of water and is fitted with a UV filter to eliminate any algae.
Number 2: Goplus Pressure Bio Filter for Koi Pond
Suitable for normal ponds of 2500 gallons with moderate fish load and a heavy fish load of 1500 gallons, this is a high-performance filter made of durable ABS material with a filter that is resistant to sunlight and aging due to water. The maximum flow rate can even reach up to 10000 L/H; with a built-in UV bulb system to improve water quality and provide efficient filtration. The filter is easy to clean and maintain with automatic cleaning functions that allow for cleaning without having to open the filter container. It has an innovative dual-outlet design with high-quality filter sponges.
Number 3: Aqua Ultraviolet Ultima Bead Filter
This next-generation filter is ideal for koi ponds designed to meet its specific demands with its lightweight and high flow rates. Its tubular media has a low head loss and a high biofilm surface. The filter has a high flow rate and only takes minutes for backwash. With two inlets and outlets, it can handle a pond of size 6000 gallons with a max pump flow of 6000 GPH. It is ideal for heavy fish loads and works equally well with low-amp high flow pumps.
Number 4: XtremepowerUS Koi Pressure Bio Filter
This 13W UV light equipped filter is ideal for koi ponds with the capability to handle 10000 per hour and is suitable for 4000 gal pond.
Number 5: Sun Grech CPF-2500 Bio Filter
Equipped with biological and mechanical filter chambers that allow for efficient removal of solid and dissolved waste. It has a simple and easy to handle cleaning system that allows for easy maintenance and allows for the rapid growth of aerobic bacteria that effectively remove lethal ammonia and nitrate. It can cope with high water flows in comparison to traditional gravity filters with completed inlet and outlet hose adapters.
Number 6: Aquascape UltraKlean Biological Filter
This filter traps dirt and debris while eliminating green water and providing optimal filtration efficiently. Suitable for 2000-gallon pond with biological pressure. Fitted with a 14W UV clarifier for efficient clarification of water and capability to handle the flow of 2700 GPH.
Number 7: Polar Aurora Pressure Bio Filter
This filter has string filtration capacity and suited for ponds with normal fish load with a capacity of 2500 gallons and a heavy fish load of 1500 gallons. It has a bulb system that reduces algae and comes equipped with multiple filtration tools. It is easy to install, operate, and clean with a sturdy and durable outer casing.
Things you Have to Consider While Buying Koi Pond Filter
There are several factors that you have to consider when buying a koi pond filter which includes:
- Your budget (most importantly). Try not to cut corners here. An all in one filter which may be somewhat cheaper will do for small ponds but for big ponds, factor in the volume and fish load as well to determine the right kind of filter that suits your needs. Again, at first, you may think this is becoming a bit too expensive; but in the long run, this will prove to be highly economical.
- Bioload produced by the fish in the pond or the fish-load in general. If you don’t factor in this correctly, chances are you will have to repeat the entire practice anew. Often neglected, this creates a lot of problems once the entire system has been installed and shows up gradually when you have to perform frequent cleaning of the media of the pond filters but the water quality keeps declining over time.
- How exposed it is to environmental factors that need to be filtered in addition to the indigenous impurities of the water. At times, some ponds are situated such that they accumulate a lot of dirt and other kinds of debris which never gets factored in when selecting a koi pond filtration system.
- Size and volume of the pond (later discussed in detail).
- Selecting the right pump. A basic rule of thumb is that the pump you choose must be able to pump all the water of your tank through the filtration system per hour.
- If there are algae in your pond or if it is prone to algae, a filter with a VU system is more suited. The high energy light of the UV system that will be integrated into your filtration system will kill the microalgae particles and prevent green water in long run.
- Analyze your requirements before opting for a pressurized or non-pressurized filter. Let’s say you don’t have any place to conceal your pressurized filter and have it placed above the surface just exposed; not a pretty sight. Similarly, if you can’t make arrangements to place your non-pressurized filter at some elevation so the gravity can work its magic, you are going to have a really bad time.
- Setting up the electronic components and making sure that you have installed the whole system such that there are no chances for any possible mishap to happen. Power cords and other components of the sort
Some personalized requirements vary from setup to setup and need to be analyzed and understood on the spot.
How to Set Up a Koi Pond Filter System?
Setting up the entire filtration system for your koi pond depends upon the type of filtration system that you have opted for. Mostly, there is an instruction manual present with each kind of filtration setup that a user purchases so it is ideal to follow the instructions provided by the manufacturer. But a few general instructions include:
- Determine the overall layout. This includes keeping in your mind the piping, filter and pump. It depends upon what you have in your mind so this step can either be really easy or quite complex.
- Determine where you will be placing your filtration setup. For a pressurized filter, this can be quite easy but a bit difficult for non-pressurized filters.
- Draw a map for laying the piping for a closed-loop that is to and from the filtration setup.
- Set up the electronics; this step varies for each setup and we advise strictly consulting the user’s manual for this. Be sure to waterproof anything that isn’t already.
Calculating the Right Pond Filter and Pump Size for Your Pond
For calculating the right pond filter and pump size, you need to consider the following three main factors:
The Volume of Your Pond
It is essential to calculate the volume of your pond so you can determine how much filtration you will need. In simple terms, the more water you have in your pond, the more filtration you will need or the capability of your filtration system should meet it adequately. Same goes for the pump. If it can’t pump the complete content of your pond through the filter per hour, then you need to get yourself a more powerful pump.
It is quite difficult to determine the exact capacity for a naturally formed pond but if you had your form you will be completely aware of the capacity and you can choose a filter as per your requirements. A simple formula would be to multiply the length, width, and height. It is advised to get a filter for your pond that is capable of handling double the volume. So if you have a guess that your pond has a capacity of 2000 gallons, then it is safe to go with a filter that can handle 4000 gallons and a pump that can pump that load through within one hour.
Water Retention Time
Again, a golden rule of thumb is that the pond water should be retained within the filtration system for around 10-15 minutes. This means that you should be turning over the entire contents of your pond and the filter almost every two to three hours. So in case of a 4000-gallon pond, an ideal turnover rate should be around 1500-2000 gallons. It is only then that we can achieve the perfect flow rate for ideal water retention.
As described above, the pond turnover for the entire contents of the pond along with the filter should be around two to three hours. For a pond of around 1000 to 1500 gallons, the required turnover rate should be somewhere between 160 to 260 gallons’ minimum which then compliments to the desired retention time.
Yes, keeping koi fish is not that easy in retrospect and we have seen that in detail in this piece. There are a lot of technical aspects to keeping koi and more importantly, there are many more technical aspects to keeping your pond in the right shape so you can keep koi fish in the first place.
The trend of keeping koi fish in either natural or constructed ponds in gaining traction and with that, it is becoming of utmost importance that people are accurately aware of the technical aspects behind keeping koi fish. They are messy and produce a lot of bioloads. Combine that with the natural and environmental factors and you have yourself a little problem. But by choosing the right filtration system with the right pumps to match, you don’t have much to worry about.
We advise that you go over the contents of the article in detail and thoroughly; we have even added some of the best and most popular filtration systems that are designed specifically for ponds containing koi fish. Hopefully, you will find the right one for you in that list. We again advise that you keep the technical aspects in check throughout the entire process of choosing and installing the right filtration system.