Exterior

How Much Does a Koi Pond Cost?

Adding a koi pond as a landscaping feature is a wonderful way to create a captivating and calming attraction on any property. Koi pond cost ranges from $450 to $100,000, with an average price of $14,000.
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Koi Pond Cost

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Highlights

  • The typical cost to build a koi pond ranges from $450 to $100,000, with a national average cost of $14,000.
  • The main factors that affect koi pond cost include the pond size and shape, excavation, liner installation, pump installation, filter type, labor, and number of fish purchased.
  • Koi ponds have many benefits, including environmental and health benefits, aesthetic appeal, and the ability for the owner to keep low-maintenance pets.
  • A koi pond is a project that’s often best left to a professional to ensure correct installation; however, with careful planning and enough skills, a handy homeowner may be able to tackle some or all of the project.
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For homeowners who want to really spice up their landscaping and be the talk of the neighborhood, adding a koi pond can do the trick. These decorative garden ponds filled with aquatic plants and colorful koi fish, goldfish, and similar species add a luxurious water feature to the yard often seen at hotels and botanical gardens. Koi ponds are known for their mesmerizing effects, helping people relax as they take in the sights and sounds of the colorful fish and trickling water. They can be constructed as an inground koi pond, as an above-ground koi pond, or as a combination of both. According to HomeAdvisor, the cost of a koi pond ranges from $450 to $100,000, with the national average being $14,000. This guide will help homeowners learn all the factors involved in koi pond design, installation, and maintenance.

Factors in Calculating Koi Pond Cost

Koi Pond Cost
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Building a koi pond to add an intriguing feature to a property involves several steps and proper installation to ensure that the fish thrive. Several key factors play a role in the total cost of the project. The size and shape of the pond are the primary factors that drive the budget. Other factors include excavation, liner installation, pump and filter type, labor, and number and species of fish purchased.

Pond Size and Shape

Although there are other factors for homeowners to consider, size is a good parameter to use in estimating the cost of building a koi pond. In general, a koi pond will cost about $75 to $125 per square foot. Homeowners can review the chart below for estimated price ranges based on pond size.

Pond SizeAverage Cost
6 feet by 8 feet$3,600 to $6,000
7 feet by 11 feet$5,775 to $9,625
10 feet by 14 feet$10,500 to $17,500
15 feet by 20 feet$22,500 to $37,500
20 feet by 25 feet$37,500 to $62,500
25 feet by 30 feet$56,250 to $93,750

It is important for homeowners to remember that the size of the pond will dictate additional costs as well. Small koi ponds will cost less overall. Larger, deeper ponds will cost more because they will require more excavation labor; landscaping; a larger liner; and a more powerful pump, skimmer basket, filter, and UV light.

With regard to pond shape, purchasing a prefabricated koi pond is the most affordable option, with a price tag in the range of $450 to $3,100. On the other hand, installing a pond with a custom shape will cost more.

Excavation

One of the first steps in pond installation is excavating the land. It typically costs $60 to $200 per cubic yard to dig the pond. For a pond 7 feet by 8 feet in diameter and 4 feet deep, homeowners can expect to pay about $500 to $1,660. Prices will be higher if the pond is an irregular shape, if the soil is rocky or made of hard clay, and if manual excavation is needed to replace equipment that can’t enter the yard. If the yard is sloped, grading and leveling services will be required and costs $40 to $180 per hour.

Liner Installation

Building a koi pond requires an effective liner to cover the walls and bottom of the pond so that water is prevented from leaking out. Deciding on the best pond liner for a koi pond can get overwhelming, since there are several styles and materials to choose from. Liner prices can range widely from $0.30 to $114 per square foot, depending on the material. Reinforced polyethylene (RPE) and high-density polyethylene (HDPE) liners are the most affordable, while concrete is the priciest. Homeowners are advised to avoid polyvinyl chloride (PVC) liners, since the material can be toxic for koi fish. Also, a pond underlayment is necessary to protect the pond liner from ripping or tearing. The typical underlayment price range is $0.25 to $0.40 per square foot. The following table shows the average prices for each type of pond liner.

Pond Liner MaterialCharacteristicsAverage Cost per Square Foot
Concrete
  • Requires professional installation
  • Permanent
  • Costly repairs if installed incorrectly
$64 to $114
Fiberglass preformed tank
  • Limited sizes and shapes
  • Most are not deep enough for an ideal koi habitat
$10 to $80
High-Density Polyethylene (HDPE)
  • Durable but punctures easily
  • Not as flexible as rubber
$0.30 to $0.70
HDPE preformed tank
  • Limited sizes and shapes
  • Most are not deep enough for an ideal koi habitat
$3.40 to $7.40
Non-toxic EPDM
  • Flexible and durable
  • Easy to install
$0.65 to $2.30
RPE (Reinforced Polyethylene)
  • More durable and puncture-resistant than HDPE
  • Stiffer than other flexible liner materials
$0.45 to $1.65

Pump Installation

The best pond pumps recirculate water in the pond to keep it fresh, prevent it from becoming stagnant, and deter mosquitos. A circulation pump for a small or medium pond runs from $50 to $500, with more powerful models costing $1,000 to $2,000 each. Homeowners will want to choose a pump that circulates the entire pond volume at least once every 3 hours. Some homeowners also install autofill valves to automatically add water to the koi pond when the water level decreases as a result of evaporation or filter cleaning. The valves cost between $30 and $100 each. Overall, running a koi pond pump costs about $10 to $70 per month, depending on the size, wattage, type, and local utility rates.

Filter Type

A thriving koi pond needs a filter to keep the water clean by removing leaves and other debris and converting harmful nitrites from old fish food and waste into harmless nitrates. A filter typically costs $150 to $1,300. The price and capacity depend on the volume of water filtered. To calculate the correct size for their filter, customers can multiply the pond volume by 1.5. The following are the price ranges for filters based on popular koi pond sizes.

Pond SizeFilter Capacity RequiredAverage Cost
7 feet by 8 feet2,520 gallons$150 to $400
8 feet by 11 feet3,960 gallons$200 to $500
11 feet by 16 feet7,920 gallons$700 to $900
16 feet by 21 feet15,120 gallons$1,000 to $1,300
26 feet by 26 feet30,420 gallons$2,000 to $5,000

Labor

Labor rates also play a role in the total cost of constructing a koi fish pond. Labor varies depending on geographic location, price of materials, and competition among contractors in the area. Homeowners can expect to pay more if the pro is traveling from another town, county, or state. The project will also cost more if it is challenging for the pro to access the spot in the yard where the pond is being installed. A consultation that entails a site visit to assess and design the koi pond is usually $80 to $450. Landscapers charge $50 to $100 per hour to build the pond and $4 to $12 per square foot for additional landscaping. To install pond lighting or an outlet, or to run wires to connect the pump to the filtration system, electricians charge $50 to $130 per hour plus a $75 service call fee. Finally, plumbers charge $45 to $150 per hour to run a water line for the pond drain.

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Number and Variety of Fish

The best part of installing a koi fish pond is inviting the fish in to enjoy their new home. Koi are a big step up from the common goldfish swimming around a fish tank. A wide variety of koi fish are available, mostly costing $15 to $55 per fish, depending on color, pattern, type, and size. The cheapest koi are $2.55 per fish, while the most expensive types have a price tag of around $100 each. Large, rare koi can even cost up to $8,000 per fish, such as the 29.5-inch Showa Isa imported from Japan. The most expensive koi fish is the Kōhaku variety. Small ones cost about $100, adults cost thousands of dollars, and the most valuable has been sold for $1.8 million. If having koi is not within the budget, homeowners may want to opt for goldfish, catfish, orfe, largemouth bass, and other similar types of fish that can live in a koi pond environment. The prices for such fish range from under $1 to no more than $10 each and are much more reasonable than the average koi fish price.

Additional Costs and Considerations

In addition to the more obvious factors mentioned above, there are several additional costs that homeowners often overlook. Permits, soil type, customizations, maintenance, and landscaping all have a price tag for homeowners to keep in mind when considering the total koi pond cost.

Permits

A construction permit may be required to build a koi pond. Homeowners will want to check with their local government and/or homeowners association (HOA) for guidelines. The average permit costs about $150. Some cities may also require a fence around the pond for approval. Additionally, homeowners will want to be aware that the size and location of the koi pond may influence the number and types of permits required.

Soil Type

The type and quality of the soil where the pond is constructed can affect the price of the project. If the soil is rocky and difficult to break through or is composed of dense clay, then the homeowner can expect to pay more in excavation fees. Also, poor soil may require that the pond be built with concrete, which costs more.

Customizations

Special features, such as bridges, statues, fountains, and waterfalls, enhance the beauty of koi ponds but increase the cost. Installing a waterfall with soothing trickling water costs about $500 to $2,500 and needs a few returning jets, which cost $10 to $50 each. Adding a water fountain typically costs $1,100 to $4,300. Other customizations include UV lights for $55 to $600 per light and an autofill valve for $30 to $100 per valve.

Maintenance 

To maintain a koi pond properly, homeowners can expect to pay between $500 and $1,500 annually. Of course, the rate for koi pond maintenance will vary depending on the size of the pond, filtration system, amount of debris accumulated, and specific repair or action needed. For this fee, a professional company specializing in pond care will do a thorough cleaning, check and clean filters, replace the UV lamp, make repairs as necessary, and prepare the pond for winter. For repairs, contractors usually charge $100 to $300 per hour for a service call, plus the cost of any materials needed. Examples include filter pad replacement for $20 to $90 along with spring maintenance or winterization for $300 to $1,200. And if a fish veterinarian is needed, a homeowner can expect to pay $50 to $100 per office visit or $200 to $300 per home visit.

Landscaping

There are also some landscaping costs for homeowners to factor in. First, before digging occurs, the yard may need to be cleared of trees, stumps, boulders, bushes, and more. The cost to clear land runs about $120 to $265 per hour. It may be worthwhile for a homeowner to budget for landscape designer costs to have a professional brainstorm koi pond ideas and handle the aquascaping details. The fee for this service ranges from $50 to $150 per hour. Planting trees around the pond provides shade and cools down the water; trees cost between $150 and $1,850 each to purchase and plant. Beautifying the koi pond with aquatic plants is also part of the process. Small plants cost anywhere from $4 to $45 per seedling. The most popular koi pond plants include lilies, lettuce, and water hyacinths. Finally, one of the best landscaping companies can install lighting to create an exquisite attraction to allow homeowners and guests to view the fish at night. Landscape lighting costs $2,100 to $4,900 per project or $100 to $400 per fixture for underwater LEDs.

Koi Pond Cost
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Benefits of Building a Koi Pond

Why would homeowners want to install a koi pond? Koi ponds are appealing additions to any home and come with many positive attributes. These include environmental benefits, physical and mental health benefits, aesthetic appeal, and the fact that koi fish make great low-maintenance pets.

Environmental Benefits

A noteworthy benefit of a backyard koi pond is the way it provides an ecosystem to attract wildlife, such as birds, butterflies, turtles, and frogs. This can increase biodiversity and protect native species. Next, the pond helps cool the air in the backyard as water evaporates. The water also provides a stable water source for plants. The pond itself provides an area for excess water to collect and pool, helping to prevent flooding and water damage on the property. Finally, by creating a koi pond as part of a home landscape, homeowners inspire a natural love and curiosity of nature, which can ultimately lead to conservation.

Health Benefits

Koi ponds provide both physical and emotional health benefits for those who have the chance to enjoy them. For starters, a koi pond transforms a backyard into a serene space that helps residents and visitors feel calm and rejuvenated. Science research shows that being around water is particularly calming, a phenomenon known as “blue mind.” From the light reflecting on the surface of the water to the calming movement of the ripples, the color blue, and the sounds of trickling water, this natural element can be a powerful stress reduction tool. In fact, it can even lower blood pressure and heart rate. Furthermore, the American Association for the Advancement of Science found that regular exposure to water increases psychological well-being and reduces the risk of mental illness. Other research found that koi ponds can also aid in recovery from injuries and illnesses. Just 10 minutes a day of koi pond time can help improve people’s health.

Aesthetic Appeal

There is no doubt that a koi fish pond brings natural beauty and visual appeal to a home that attracts anyone who has the opportunity to enjoy it. A koi pond can be a focal point in the yard. By adding special features like a waterfall, natural stone, and colorful landscaping, the koi pond can be even more aesthetically pleasing to homeowners and their guests.

Low-Maintenance Pets

For those who are seeking a pet but who are uninterested in the responsibility of walking a dog or grooming a cat, koi fish can be an easy and enjoyable option. Koi fish can stay outside year-round; be left for weeks at a time, since they can feed on algae and bugs in the pond; and require much less maintenance and care in general than other types of pets. Surprisingly, studies show that people can build a connection with the koi, since they are known to have distinctive personalities and enjoy interacting with humans, especially those who feed them. It can be a fun and engaging experience to care for the koi fish, such as feeding them, checking temperature levels, taking water measurements, and observing how they move around in the water.

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Koi Pond Installation: DIY vs. Hiring a Professional 

Although it is certainly possible to install a koi pond as a DIY project, it is not often recommended, since a lot goes into ensuring that the ecosystem is healthy and comfortable and that the fish can thrive. For those who want to pursue building their own koi pond, a prefab kit can be purchased for $500 to $6,100. The endeavor takes careful planning, time, patience, and the right equipment, such as a pump and filtration system.

Homeowners who want to tackle the challenge of planning a backyard pond head-on can consider the following steps.

  1. Plan. Decide on the general pond size, location, and features. Check whether permits are necessary for the project. Determine what land clearing needs to be done before breaking ground.
  2. Design. Map out the specifics of the pond, such as shape, dimensions, location, as well as the pump and filter location.
  3. Dig. Clear the area and dig the pond. The sides should be straight down, and the bottom should slope to the center drain.
  4. Install liner. Line the pond with underlayment followed by a fish-safe liner. Extend the liner at least 12 inches beyond the pond’s edge, and use rocks to secure and hide the liner.
  5. Secure components. Attach the liner to the filtration system with a safe sealant.
  6. Add water. Fill the pond with water, and test it to ensure it is safe for the fish.
Koi Pond Cost
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How to Save Money on Koi Pond Cost

If homeowners are not careful, the cost of a garden koi pond can really add up, from the materials used to construct it through the type of fish swimming around in it. Fortunately, there are some tips and tricks to cut costs throughout the process.

  • Raise baby koi fish. Purchasing adult koi costs much more than purchasing young ones and raising them.
  • Dig the pond. By making this a DIY project, homeowners can save money by digging their own ponds. This can be done simply with a shovel and enough time or with mechanical equipment rental to assist with digging.
  • Shop around for the liner. Since having a quality liner is critical, it is a good idea to compare prices at stores and online.
  • Look for deals on plants. Purchase water plants from various locations, including nurseries, garden centers, and even online resources like eBay.
  • Avoid concrete. Building with concrete will be more expensive and take longer. The result will also not be as natural looking.
  • Opt for goldfish. To really cut costs, choose goldfish instead of koi fish to fill the pond.

Questions to Ask About Koi Pond Installation

Outdoor koi ponds are an appealing and soothing addition to the landscape, but there are some details to pay attention to when homeowners are choosing which pro to hire. Homeowners will want to do research, such as asking for recommendations and reading reviews online. Getting multiple quotes is also a good idea when comparing companies. It is important for homeowners to choose one that can bring their vision to life. What follows are some questions for homeowners to ask pond contractors before getting started on the project.

  • Are you licensed and insured?
  • Do you specialize in pond design and construction?
  • How many years have you been in business?
  • Can you provide pictures of your previous pond work?
  • What construction method do you use to build the pond?
  • What minimum size and depth do you recommend for koi in this climate?
  • How many koi fish can I keep in a pond this size?
  • What is included with the installation?
  • What add-on features do you offer?
  • Do you provide koi fish for the pond?
  • How long will the project take?
  • What brand and type of pump and filtration systems do you install?
  • What type of guarantee do you provide for your work?
  • Do you offer maintenance services?
  • What can I expect my monthly operating and maintenance costs to be?
  • Should I bring the koi inside for the winter?

FAQs

When homeowners are deciding whether to install a koi pond on their property, it is important for them to ask the right questions and understand what they will pay for the project. The cost will depend on many factors, such as pond size, labor, filtration, and number of fish needed to fill the pond. It is essential for homeowners to realize all the costs involved in preparation, installation, and maintenance to reduce the risk of getting an unexpected bill. For those exploring koi ponds and all that they have to offer, the following are a few questions that may come up.

Q. How much are koi fish?

A wide variety of koi fish are available, mostly costing $15 to $55 per fish, depending on color, pattern, and size. The cheapest koi are $2.55 per fish, while the most expensive types have a price tag around $100. Large, rare koi can even cost up to $8,000 per fish.

Q. How long does it take to build a koi pond?

It takes one person about 5 days to build a small koi pond. To install a medium pond, it takes a crew of three workers with an excavator about 5 days. For one person to do that same job would take about 2 weeks. To construct a large koi pond, it takes five workers 7 to 10 days using an excavator and skid steer. For one person to get that same project done, it could take up to a month.

Q. How do I maintain my koi pond?

Although a koi pond is generally low maintenance, the fish need to be fed and the skimmer basket emptied when full. Other tasks include removing any debris floating on the pond, such as leaves and branches; checking and cleaning filters; replacing the UV lamp; preparing the pond for the winter season; and making repairs as needed. Professional pond maintenance services are available for $1,000 to $2,000 every few months.

Q. Can koi live in a 500-gallon pond?

Yes, mature koi need at least 250 gallons of water to live in. More water will be necessary if there are lots of fish and/or if they are large, such as over 25 inches long. For three jumbo fish at around 36 inches long, 1,000 gallons will be needed.

Q. Do I need a permit to build a koi pond?

Installing a pond often requires a construction permit, but homeowners will want to check with their contractor and local government for specific guidelines. The average construction permit costs $150.

Q. Do koi ponds increase home value?

Since koi ponds are a very custom and unique feature to add to a home, there may not be an obvious increase in home value as a result of building one. However, a koi pond could be attractive to a potential buyer and boost the marketability and curb appeal of the home.

Sources: HomeAdvisor, HomeGuide, LawnLove, LawnStarter, Amen Corner Ponds