The Best Pump for Koi Ponds & Heavy Stocked Fish Ponds 2021 (updated)
Selecting a new pump can be a long process, and the choice becomes even more difficult if you intend to add koi to your pond. In this article we’ve performed the research for you, selecting what we feel are the best koi pumps on the market, with main consideration towards overall reliability, water turnover rates, head heights, and monthly running costs.
|Aquascape AquaForce Submersible Pump||MaxPro Legends External Koi Pumps||Elite Pumps Pro Self Priming Range|
What to Consider when Selecting a Koi Pump?
Although many types of pumps will be suitable for ponds with fish, there are still some features which make certain pump models more desirable for heavy stocked koi.
Unlike having a pump in a fish-less pond, where water turnover and filtration is less of a concern, having koi carp means you need to be a little more specific in what you choose. For example, fish produce a lot of waste throughout the year and this contributes to rising ammonia and nitrite levels – both of which are toxic to aquatic life. Water turnover means the amount of time it takes for a pump to cycle all pond water through the filtration system, and if you have koi stock, you’ll want this done every hour for the best water quality. A weaker pump would not be able to move water efficiently enough for your biological media to remove harmful substances produced from fish waste, meaning it would slowly rise to dangerous levels.
Another point to take into account is the fact that koi ponds will be generally larger and deeper than ponds with smaller fish, so you’d need a pump with sufficient water lift heights. If your pump can’t efficiently move water throughout your system it won’t be suitable for the pond, and you would need to find something stronger with greater maximum head so there is no loss in pressure.
On the same note, since koi ponds are usually fairly large in volume, you would also want to take energy efficiency, monthly running costs, and the type of pump into account. The two most common types, submersible pumps and external pumps, both have their places in fish keeping, however one may be more suitable than the other depending on your circumstances. Likewise, certain pumps are more efficient than others, so making sure you purchase one with good energy saving potential will save you a lot of money in the long run.
To summarize, you want to consider:
1) Flow Rate (Water Turnover)
Water turnover needs to happen once every hour, so if you have a 6,000 US gallon pond, you would need a minimum flow rate of 6,000 GPH from your pump pond. This will ensure all pond will can pass through your filtration system every hour for the removal of harmful waste substances. Good water filtration is at the heart of every healthy koi pond, and the pump is what powers it!
2) Water Lift Height
Depending on the location of your filter box and what type of pump you install, you should also consider the maximum “head height” rating. For example, if your filter box is installed above ground at 3 foot of height, you would need to make sure your the flow rate is still sufficient at this height for once hourly water turnover to occur.
3) Monthly Running Costs
Ponds with koi are generally larger than regular ponds, so you’ll want to keep costs as low as possible whilst still retaining good water flow. Certain models of pump are cheaper to run than others, with externals being generally better for ponds over 6,000 US gallons compared to submersible models. We’ve worked out the costs for each of our chosen pumps in the reviews, and there is also a section further down in this article which helps you calculate the costs manually if you like to run the numbers yourself.
What is Better for Koi – External Pumps or Submersible Pumps?
Both external and submersible pumps have their place, and both have their advantages and disadvantages depending on your situation. For most regular pond owners, or for those with lower levels of fish stocks (1-2 koi), submersible models can be an overall cheaper option. With that said, external models can be a better choice if you have a larger pond or high fish stocks, with ponds over 6,000 US gallons often benefiting from reduced running costs at this range. We’ve detailed our thoughts on this below in terms of koi ponds, as well as listed general pros and cons of each type for a pond with koi stock.
1) Submersible Koi Pumps
Submersible pumps may be an easier and more cost effective option for small ponds with low koi stocks, as they’re simple to install and won’t cost much to run monthly. As the name suggests, these type of pumps are installed under the water and don’t can’t operate “dry” at ground level. They’re discreet and cheaper to purchase, although you won’t have as much power as an external pump so they may not be the best choice for ponds 6,000 US gallons or larger. We recommend submerged models for pond owners who have koi ponds within 1,000-6,000 gallon range, or if you have lower fish stock levels. The energy savings from external pumps only start becoming noticeable at higher flow rates, and they’re much harder to install and more expensive to purchase. Water lift heights are also respectable for top quality submerged pumps, so you shouldn’t have a problem moving water to an elevated filter box if needed.
2) External Koi Pumps
Although harder to install compared to submersible pumps, external models are a great long-term investment if you have a larger pond or a pond with heavy koi stocks. The main benefits from using an external pump over a submersible for larger ponds is the higher energy efficiency and more powerful flow rate options. External pumps excel in saving you money at higher flow rates, and we would strongly recommend them to fish keepers with ponds over 6,000 US gallons. 9 times out of 10 a quality external pump will outperform a submersible above this range and will STILL cost less to run each month. As well as this, external pumps are just that much more powerful, meaning more options for massive ponds or for fish keepers who want maximum water turn over. The purchase cost is higher than submersible pumps, but so long as you work out monthly running costs, you could be saving much more in the long run.
A final thing is external pumps have many extra features that may be handy depending your situation. For example, a common feature is dual voltage control for 115v and 230v lines so you have more flexibility at the site of installation Another feature is priming pots which sit on the front of the pump filtering leaves so the pump doesn’t clog, effectively improving your water filtration.
Koi Pond Pumps – Common Questions Answered
Q) How to install a koi pond pump correctly?
Installation would depend on the type of pump you purchase, as well as it’s maximum water head height value. If you choose a submersible pump it would need to be placed under water, preferably at the deepest point of the pond. While installing you would need to take into account the depth of water, as well as making sure the pump can move water efficiently to the height of the filter box. If the pond is 3 feet deep and the filter is installed 1 foot above ground level, you would need sufficient flow rate at 4 feet of head height. So for a 4,000 gallon koi pond you’d want a pump that provides 4,000 GPH at 4 feet of head height, so you may need to purchase a higher rated base model to achieve this – i.e, 5000-6000 GPH.
For external pumps they would need to be installed below ground level, usually in a hole next to the pond itself. This is because external pumps need to be “primed” before use with water, and this can be very difficult at and above ground level. Self-priming pumps have it easier as they can mix both air and water into a special fluid for operation, but they still need water to start and cannot operate on just air alone. Priming pots come pre-installed on self-priming pumps, but can be added separately to make priming easier for regular flooded suction models.
Q) How long should a koi pond pump run?
24 hours a day, 7 days a week. Keeping koi ponds healthy is all about providing the best water filtration and aeration; both of which require an efficient pump. Unlike in ponds without fish where you won’t face many problems switching off your equipment, as soon as a pump stops in a koi pond so does water filtration. Fish produce waste constantly, and waste is high in ammonia which needs to be kept to a minimum. Without constant filtration beneficial bacteria cannot efficiently break down harmful substances and eventually water quality begins to degrade. This will lead to fish becoming sick, unhealthy, and stressed, and it can be difficult to recover from a spike in ammonia without harm to koi.
Although it can sound costly to have a pump run non-stop, it is still a necessary part of koi keeping that can’t be avoided. Luckily, you can knock huge amounts of money from your monthly bill by selecting an efficient pump, as well as keeping on top of general cleaning and maintenance.
Q) How much will a koi pump cost to run monthly?
One of the most important questions when installing new equipment – how much will it cost? Since you’ll be running your pump 24/7, high efficiency is key for long term savings. We’ve worked out the running costs for our reviewed models below to make it easier, but if you have a different pump in mind you can use the formula below. You’ll need a recent electricity bill for the most accurate answer and your how much you pay per kilowatt hour. You can also just use the US national average of $0.10 for a ball park figure!
Step 1: Koi Pump Wattage x Daily run time in hours (24) = Total Daily Watts
Step 2: Total Daily Watts / 1000 = KiloWatt per hour (kWh), per day
Step 3: kWh per day x Monthly run time in days (30) = kWh per month
Step 4: kWh per month x cost of 1 kWh from your electricity bill (or $0.10 national average) = Total Monthly Cost
Best Koi Pond Pump Reviews 2021
Below are some of our top koi pump recommendations, all of which have been chosen based on their reliability, energy saving potential, and strong flow rates and head heights. Both external koi pump (flooded suction & self-priming) and submersible koi pump options have been included.
Our top choice of underwater koi pumps is the powerful Aquascape Aquaforce series, bringing high flow rates, head heights, and good energy efficiency to submersible models.
These pumps are ideal for koi ponds below 6,000 US gallons and can operate almost as efficiently as an external pump due to their asynchronous motor technology. Unlike some other submersible pumps which operate using magnetic-drive or direct-drive motors, Aquaforce’s asynchronous motor allows the pump to provide the same amount of flow rate but at lower operational costs and better head heights. The pumps range in requirements from 55w (entry model) to 360w (top model), which is extremely efficient for such powerful submersible pumps.
On top of the great energy efficiency the pumps also provide a range of different flow rates and head heights, making them flexible for all sizes and depths of ponds. The water lift heights range from 10 ft (1000 model) to a maximum of 25 ft (5200 model), so you can select a pump based on your filter placement and pond depth. The water lift heights are comparable to external models, and although they are less energy efficient at the higher flow range, you’d be hard pressed to find a better option for a submersible pump!
To prevent clogging the pumps all feature a durable pre-filter cage design, which does a good job of holding back most common debris, such as leaves, twigs, and algae clumps. Since most koi ponds need to be cleaned from sludge and debris anyway, you shouldn’t have any issues with clogging if your pond is regularly maintained
Since this is a submersible model it will need to be placed inside the pond and cannot operate externally. Even under max operational load the pump motors stay fairly cool, thanks in combination to the surrounding pond water and a great internal cooling system to prevent damage. The pumps come with a very generous 25ft cable, too, which makes it very easy to install even in the largest of koi ponds.
The only drawback of these pumps is they’re still a little less efficient than external models, but are much cheaper to purchase at lower flow rates. Once you get up to around 6,000+ gallons, however, we’d recommend moving over to a quality external pump as they will be able to provide more raw power and better energy savings over time. If you have a low-stocked koi pond or a pond under 6,000 gallons, these are some of the best submersible koi pumps on the market, providing great efficiency, reliability, and head heights at a reasonable price point.
How much will this koi pump cost me to run?
Assuming a charge of $0.10 per kWh (national average), the cost to run the 1000 model pump monthly would be $3.96 per month, and the cost to run the 5200 model would be $25.92 per month. This would be running the pump 24 hours a day, 30 days a month.
- Type: Submersible Koi Pump
- Maximum Flow Rate: 1070 GPH – 5284 GPH
- Maximum Head Height: 10 ft (1000 Model) and 25 ft (5200 Model)
- Power Consumption: 55w (1000 Model) to 360w (5200 Model)
- Power Cord Length: 25 ft (7.6m)
- Outlet/Input Size: 3/4″, 1″, 1.25″, 1.5″, 2″ ID Tubing
- Warranty: 3 Years
Most Efficient External Koi Pump
One of our top rated koi pumps in our main external pump article is the MaxPro Legend external pump range! We love this external pump as it provides some of the best energy efficiency in the industry thanks to it’s custom LOW RPM fan-cooled motors and overall low energy draw. The purchase cost is on par (or lower) than other similar external pumps, but the energy savings are much higher thanks to it’s fantastic efficiency at high flow rates.
The MaxPro Legend series are available in a wide range of ratings, ranging from 3,000 GPH (entry model) to 10K GPH+ power houses. They’re a great choice for all sizes of koi pond, being particularly ideal for massive ponds 8,000 gallons+ due to their power and energy saving potential.
They feature some respectable water lift heights, ranging from 17ft (3000 model) to 22ft (10000 model), so should be suitable for both filtration systems and water features if needed. The head heights are a little lower than some others in the industry, but if you’re just using this to power a large filtration system, you should see no problems with drops in water pressure.
This pump is an external model so needs to be installed below the water line, preferably with a priming pot on the intake for easier operation. They’re not self-priming so more care needs to be taken when starting the pump, and this is why we strongly recommend a wet install and a priming device to help.
In terms of reliability, these pumps have been designed to work flawlessly 24/7, and even come with a 3 year warranty for maximum peace of mind. They’re durable and weather resistant, although we would still advise covering the pump to minimize general wear and tear. The pumps operate on 115v lines, which is common for most external models, and do not have a default option for 230v control. We would have liked to see more flexibility in the top-end models for speed and voltage settings, but the pumps are so well priced we can’t really complain!
We highly recommend these external pumps for large koi ponds or for pond owners looking for maximum power and energy savings. They’re a great choice for ponds between 6-10k US gallons, or for pond owners who want reliable operation and powerful flow rates at a very reasonable price.
How much will this koi pump cost me to run?
Assuming a charge of $0.10 per kWh (national average), the cost to run the 3000 model monthly would be $14.5 per month, and the cost to run the 10000 model would be $31.5 per month. This would be running the pump 24 hours a day, 30 days a month.
- Type: External Centrifugal Pump
- Priming method: Flooded suction (Non Self-priming)
- Voltage: 115v
- Maximum Flow Rate: 3000 – 10,000 GPH (depending on model)
- Maximum Head Height: 17-22 ft (depending on model)
- Power Consumption: 201w to 438w (depending on model)
- Power Cord Length: 15 ft (2.4m)
- Outlet/Input Size: Fits 2 inch (ID) tubing
- Warranty: 3 Year
Top Self-Priming External Koi Pump
If you’re looking for the great energy savings of an external, but want something easier to handle, Elite Pumps Pro 2 Self-priming range may be the ideal choice. These pumps are some of the most affordable self-priming models around, and require much less work to get operational compared to classic flooded suction designs.
For regular flooded suction pumps, the main chamber would need to be filled with water with no air retention for the pump to work. You would also need a priming pot to prevent damage, and a deep below ground install for water to reach the motor chambers. This leaves a lot of room for error and pump damage, and that’s where self-priming pumps come in! These pumps can function on a mix of both air and water, creating a special fluid for operation. This makes starting the pump much faster the first time around, and they even retain water in an internal reservoir for easier self-priming in future. Priming pots (leaf baskets) are also built in as standard, making self-priming pumps a good choice if you want a “all-in-one” external koi pump without the usual hassle of priming problems.
In terms of flow rates, this range comes with models ranging from 4,000 GPH to 9,000+ GPH, so would suit both smaller and larger koi ponds. Maximum head heights are particular good, with the lowest models delivering 19 ft of water lift and the top end models providing a massive 27 ft of maximum head. If you have your equipment in an elevated position, or want to also power additional water features, these are a solid pick.
One of the biggest selling points of this particular self-priming range is the amazing energy saving potential. Regular flooded suction pumps will always be cheaper than self-primers, and if you choose a low quality self-priming pump, your monthly electricity bill can sky-rocket. Luckily, these are some of the most energy efficient self-priming pumps we’ve found, with the highest models running almost in-line with flooded suction pumps in terms of costs. Since koi ponds require constant pump operation, efficiency should always be a primary objective, and Elite Pro Pumps has that aspect covered!
The pumps also feature dual voltage control for both 115v and 230v lines, so may be useful if you need both options or the less common 230v at the site of installation. A 3 year warranty is included as standard on all models for maximum peace of mind, which is always a bonus.
Overall, one of the best self-priming models for koi ponds with very good energy efficient ratings and powerful maximum head heights. They’re more expensive than flooded suction pumps, but if you want to save time with priming and need more features from your pump, this is a good all-in-one external pump choice.
How much will this koi pump cost me to run?
Assuming a charge of $0.10 per kWh (national average), the cost to run the 4000 model pump monthly would be $14.7 per month, and the cost to run the 9600 model would be $45 per month. This would be running the pump 24 hours a day, 30 days a month.
- Type: External Centrifugal Pump
- Priming method: Self-Priming (Priming pot included)
- Voltage: 115v/230v (dual voltage control)
- Maximum Flow Rate: 4000 GPH – 9500 GPH (depending on model)
- Maximum Head Height: 19-27 ft (depending on model)
- Power Consumption: 204w to 624w (depending on model)
- Power Cord Length: 15 ft (4.6m)
- Outlet/Input Size: Fits 2 inch (ID) tubing
- Warranty: 3 Year