What Is A Koi Pond And How To Create Your Own – Ultimate Guide

Why have a Koi pond?

Many homeowners dream of one day having a water feature on their property, a beautiful water garden.

It can be a visual rest station, a relaxing pit stop during the day. While it most certainly can be an attraction to your visitors it also can be a place to visit at the end of the day to reflect on daily events and plan for the future.

Having a Koi pond can be particularly satisfying.

Why are koi fish so special?

In most Japanese cultures, koi represent material and spiritual abundance or advancement. Feng shui, a spiritual form of organization and placement of objects, says that having the spirit of the koi near you will attract good luck, fortune, and spiritual benefits.

What is a Koi Fish Pond?

Koi ponds can be the best of all outdoor ponds, with some representing the most tranquil and peaceful scenes in the world.

Koi ponds are aesthetically appealing and picturesque, they are nature friendly and relaxing, as well as often raising property value.

Having a Koi pond in your garden is more than a big fish tank or swimming pool, it is a symbol of style and helps to add a certain element of elegance to your garden, much more than just a backyard pond.

Koi have a long and extremely colorful history in the fish keeping industry!

Are koi and carp the same thing?

Koi are a domesticated version of the common carp, they are a subspecies. Unlike the common carp, koi have been selectively bred to have vibrant, bright color variations and patterns. If they were left alone in the wild, koi would breed with carp.

Let’s build a KOI POND

We are going to go over everything you need to know about Koi ponds from indoor and outdoor kits, to DIY ideas, as well as a step by step guide on building your own Koi pond.

There are three ways to build a pond. Hire a contractor, buy a kit DIY, Do-It-Yourself. The cost to hire a contract varies from location to location, different size ponds, and the specifics of the ponds.

We have found the cost ranges from a low of $7,000 to the sky is the limit, but a typical pond costs about $17,000 in the United States.

Koi pond kits provide Fish Keepers who are relatively new to Koi keeping with a complete setup that is simple to put together.

The main benefit of kits is that it saves people time, which would be spent researching all of the different parts and components that are needed to build your pond. Kits are limited to manufacturers specifications, quality of components, you do the labor, prices run $600 to $5,000 in the United States. DIY Ponds provide you with the chance to build the pond you have always talked about.

You will need to spend time planning your pond. 

Researching components and designs will give you the exact pond you have wanted.

Indoor Ponds

Indoor ponds tend to be less expensive because they are smaller.

Indoor ponds are often bought as kits that come as raised, durable plastic containers that also have built-in windows to view inside activities and a wooden or plastic outer shell.

These indoor ponds come with features like ultraviolet light, fountains, and waterfalls but require the correct pumps to operate.

DIY Koi Pond

Koi ponds are different than garden ponds. They are built with the specific purpose of housing and growing your Koi. It will be necessary that the pond is created so that the fish’s needs are met for a safe and healthy life to ensure their survival.

Since you have decided to build your own Koi pond you need to start putting your plans and dreams to paper. Building and maintaining a Koi pond will be a long-term project, if done correctly it will be a very satisfying experience. The best plan will reduce any regrets in the future.

When doing your research and planning you will come across conflicting information and ideas. It is best, and you will have the most success if you chose one plan that has a successful history and stick with it rather than trying to incorporate different pieces of advice into one plan.

Before buying a product or making any investment try to get out and visit some Koi ponds in the local area. Most Koi Keepers are proud of their pond and happy to share their experiences, and they happy to volunteer invaluable advice about the cost of equipment and supplies, what decisions meant down-the-road, what decisions in hindsight they wished they had made, and where to find good quality materials at a fair price.

Most pond owners will tell you that the enjoyment they get out of these beautiful fish far outweighs any of the hard work and expense that went into their prized project.

Try Googling Koi Club for clubs in your area. Once you have done this research and footwork you will understand the project you have taken on and how it fits into the budget you have available.

Design the Pond

The first step is to pick the right location, then to determine the size and depth you want the pond to be. Then calculate how much water will be in the koi pond. That will tell you what size the filtration system needs to be.

There needs to be enough room to install a large enough pond, some smaller backyards might not allow the room for your ideal pond style.

You probably want a fabulous view of your beautiful water garden so visibility is important. If you want to include the koi pond into your larger outdoor designs, it should be easily visible and accessible. 

A space that is already level and not constantly shaded will create an ideal environment.

Determining Pond Size, Shape, and Depth

What size, shape, depth, and total volume to make your pond are your first big decisions. An estimate to start with for a Koi pond would be 25 feet long by 13 feet wide with a minimum depth of 3 feet.

Ponds can be smaller, but you really shouldn’t stray too far from those measurements. If you do, your koi will struggle to grow.

Try to limit the width of your pond to no more than 13 feet, anything larger will make it more difficult to catch the fish when necessary, and at some point, it will become necessary.

For your fish safety, you should make at least a 3 ft deep pond so they can escape predators. At a minimum of 3 feet deep it is less likely your pond will fully freeze over during winter. 

Depending on the size of the fish within the pond, you may want to add a mesh cover to prevent larger birds like Blue Heron, Stalks, or Cranes from praying on smaller juvenile fish.

A rectangular shape rather than a rounded pond will maximize the pond area.

Calculating Water Volume is Simple for your Pond

This is important for proper filtration and also water quality.

To calculate your pond’s volume in gallons, you simply multiply the length by width by depth by 7.5 gallons per cubic foot. So, taking the above measurements, you would multiply 25 by 13 by 3 by 7.5, meaning that the volume of water in your pond would be 7313 gallons. It may be tempting to go with a smaller pond to minimize cost and labor but you may find a larger pond will save you from adding additional ponds later as your fish grow.

Many fishkeepers start with a small pond and end up spending more as they add more space. To be sure your koi exercise enough, stay healthy, and avoid stress, you need to make the size of your pond a priority.

Filtration System and Testing Kits

Your filtration system and testing kits should be the first things you budget for when planning a pond. Pond supply retailers are the perfect place to go for quotes on filtration systems, testing kits, and other supplies, and they will help you factor in the overall cost for your pond before you start building. Always factor in all potential costs in your early planning stage so that you’re not caught by surprise later on.

Choosing the Right Filter Size

The size of these filter systems is crucial, and you’ll need to consider many factors when deciding what will work best for you. 

Most filtration systems will state the size of the pond they’re rated to filter, but be aware that this doesn’t tell the entire story. For instance, an approximately 2 by 2 by  3-foot box may say that it can take care of 6000 gallons of water, but this would be true only if the pond contained just a few fish, less than 5. 

When you’re looking for filters you should also be sure that you ask how many 20-inch fish the filter can support when they’re fed normally. 

By balancing the size of the pond with the volume of fish, you’ll know that you can raise your koi with minimal risk of exposing them to harmful chemicals. 

Buying the filter system before populating the pond will make sure that, if checked regularly, your pond will be a livable habitat.

Outline the Pond

Once you have your plan on paper, mark out the dimensions of your pond directly onto the ground. Choose a shape for the pond to be based on the dimensions that you have decided. Use either rope, a garden hose, or spray paint to make sure that you are happy with the size and location of the pond. 

You should also outline where key components of the pond like the skimmer, falls and filtration will be placed.

This will let you visualize the pond and build anticipation for your project.

Excavating the Pond

With everything outlined, you can now start digging the pond.

You can use a sturdy shovel, or if you want to get the work done faster get a friend to help. Better yet rent a small excavator from your local big-box store and start digging. It is easy to use and will let you move your soil by loading it into wheelbarrows. The same soil can be used to cover the pond skimmer, pre-filter, aeration, and other installation you don’t want to be seen.

You should add different levels and shelves to the pond as different plants will occupy different tiers and depths of the pond so they get the correct sunlight. 

The lowest point of the pond should at least 3 feet deep.

Digging the Trenches for Equipment

Now to dig trenches for the plumbing to go from the pond to the external filter and/or waterfall. Pond skimmers will need to be buried at the correct levels beside the pond.

If you choose to use a skimmer, you will need to dig a trench to the external pond pump and from the pump to the external pond filter and/or waterfall. 

If you use a submersible pump for the skimmer then the trench will go from the skimmer to the waterfall/filter.

Installing Bottom Drainage

Bottom drainage is used to remove the fish waste from the bottom of the pond. Having one will save you time since there will be less maintenance needed.

Dig a hole in the center of the deepest section of the pond where the drain will sit. The bottom section of the pond should be cone-shaped so that gravity will do the work of moving the waste towards the drain.

Then dig a trench for the flex pipe that connects the drain to the vortex and settlement tank of the filter. After connecting these components, backfill the hole and trench with dirt leaving only the intake exposed.

To ensure good water quality a bottom drain is necessary that continually gravity feeds to the filter system. Constant gravity feeding allows it to sweep everything down to the bottom of the drain for the elimination of organic sediment and aerobic bacteria.

By using a gravity-feed filtration system the water will constantly circulation, and your fish are less likely to die from a disease. Of course, a bottom drain isn’t enough; you will also need a large enough filtration system that includes the following elements:

Settling Chambers

Create a current jet down two-thirds of the way down the container to push water in a circular pattern and that’s gonna work in a vortex kind effect and push things down to the bottom drain as well.

Water will enter this system on an angle which will create a swirling motion that forces the larger pieces of debris to the sides. The gravity will draw the larger pieces down to the bottom of the pond, where the purge line will enter the purpose-built container. This makes maintenance simple, when the debris has accumulated, you can easily pull the knife valve to get rid of the waste. 

For most Koi ponds, this container should be a minimum of 40 inches in diameter and 40 inches deep.

Mechanical Filtration

A mechanical filtration system will remove suspended debris from the water as it passes through the filter. 

The filtration system must be directly in the path of the water flow. Cylindrical brushes work best, you want them to be made of a steel core with nylon bristles. To ensure maximum exposure, you’ll need four rows of brushes, and you’ll want them to overlap. They will also need to be cleaned regularly to ensure they are properly working.

Biological Filtration

The Biological filter allows beneficial bacteria to convert harmful ammonia and nitrite into less toxic nitrate. 

There needs to be enough of this nitrifying bacteria to keep pace with the decomposition of fish waste, uneaten food, and other organic material in the pond, so this is a delicate balance to maintain proper filtration. 

That is why overstocking and overfeeding a pond are among the most harmful things you can do as a Koi Keeper. 

To see whether biological filtration is working effectively in your pond, you’ll need to test the water regularly with an inexpensive, but effective test kit.

Underlaying the Pond

Now fit underlay to the pond. The liner should extend about a foot out of your pond. 

Anchor with large rocks. Smooth lining the best you can. Make sure if you’re walking around in the pond, not to rip your liner. 

Cut an X in the underlay where the bottom drainage will be.

Lining the Pond

Once the underlay has been fitted, you need to line the pond.

Order a one-piece pond liner from a home improvement or landscaping supplier. Install the liner as per the manufacturer’s directions. Have several people help you to roll it out over the pond. Make sure that it overlaps the edges of the pond.

If you are using multiple pond liners in your waterfall, use seam tape, and primer! Lots of online tutorials simply mention overlap. If you seal the seals properly you will never worry about under seam leaks and roots finding water and growing.

Learned Tip: Multiple sources said to make sure that there was at least 1 foot of liner hanging over the side when the pond is complete.

Connecting the Bottom Drain and Skimmer

The bottom drain and pond skimmer constantly remove waste, excess nutrients, and debris from the pond floor, so the pond doesn’t have to be drained.

After laying out enough liner to cover the bottom and side of the pond, cut an X into the bottom of the liner where the bottom drain is going to go.

Once done, make sure the drain and liner are clean and dry before gluing them together and remove any wrinkles. Then screw the top section of the drain to the bottom half which is coming up from the pond to form a tight seal and prevent any leaks.

When this is done there will be four small triangles of excess liner inside of the drain where the X has been cut, cut these off to allow water and debris to pass through to the bottom of the drain.

For the skimmer, follow the manufacturer’s instructions and place the piping in the correct position, making sure to leave a couple of additional inches of piping to allow for the connection.

Edging the Pond

This is entirely up to you, tiles tend to give it a modern look, while large rocks add a more Mother Nature feel to the pond bricks.Place rocks over the liner around the edge of the pond. Use large stones and rocks to completely cover the liner that is at surface level, leaving only the hole for the pond exposed. 
Stack and overlap the rocks using whatever design that you prefer. 

Make sure that at least 1 foot of the liner is exposed beyond the edge of the rocks, this will prevent rainwater from getting into the pond. 

Cement them in place.

Adding Water and Bacteria

Fill the pond to the correct water level and add a water conditioner to dechlorinate the water.

Starter bacteria may be bought and should be added to the water. The filter should be installed and turned on along with any pumps.

You should also add a heater to the pond and turn it on. Allow the temperature to stabilize in the 59-77F range.

Planting the Pond

The next step on the list is adding aquatic plants to your pond.

Add all of your plants to the pond and place them on their corresponding tiers/levels and in positions where they will get their correct amount of light.

Allow time for both the bacteria and plants to establish themselves first before adding any fish. Fast-growing plants work best in Koi ponds where the fish will eat the plants if they get hungry.

The below link gives some plant suggestions.

An excellent source for plant ideas.  LINK

Check Water Parameters

If you have a small pond the water temperature and pH can change rapidly, causing harm to the fish. Another side effect of a small body of water is that waste buildup will limit the size of the Koi living in the pond and the shape and size of the fish will likely be hindered by a lack of swimming space.

Taking a closer look at what is needed for Koi to grow properly and how you can overcome any temperature and pH fluctuations also any filtration issues. Have a test kit on hand and do all of the necessary tests to make sure the nitrogen cycle has finished. This should not take as long if you add bacteria beforehand.

You will notice the ammonia and nitrite levels spiking then going back down to zero this indicates your pond is ready for fish, maintaining proper water quality is important.

The cycle can take from 2 to 8 weeks to complete.

Good Water Quality

Good water quality is the main factor in successfully keeping koi: pH, ammonia, nitrite, and nitrate levels in the water should be checked regularly.

Ideally, the ammonia and nitrite levels should be zero, pH levels between 7.0 and 8.0 are good and the nitrate level should be kept below 50 ppm, but the decomposition of excessive organic matter can cause levels to rise too high, so they must be monitored closely.

When you’re running water to your pond, never use straight tap water, as it contains toxic levels of chlorine or chloramine. It must first be treated to neutralize those chemicals.

Adding Fish

Be sure to acclimate the fish before placing them in the pond. This can be done by floating the bags on the pond’s surface for about 30 minutes.Do this by keeping the koi in the water and in the plastic bag that they were purchased in. Float the plastic bag in your koi pond for 30 minutes so that they can adjust to the temperature change. 
Then add a bit of pond water into the plastic bag, tie it up, and let it float for an additional 30 minutes to help the koi adjust to the pond water.

Next, gently pour the fish from the bag into a net above a bucket and add them to the pond. Do not add the water from the bag to the pond just dispose of it.

What Other Types of Fish Can Live in a Koi Pond?

One of the nice things about a koi pond is that Koi get along well with other non-aggressive fish.
Koi can live happily with other freshwater fish such as goldfish, telescopes, lionheads, orandas, black moors, and Ryukins but not every type of backyard pond fish.

Large fish may eat smaller fish.Before buying a new species, research how that species will get along with the koi and what kinds of demands it will put on the maintenance of the pond: added food and waste, plus how large will they grow.

Koi Pond Plants

Koi are known for eating plants, so they must be kept well fed to ensure the longevity of the plants in your pond.

Choosing the right plants is important, the ones which do best are generally the ones which grow fastest.

Different plants require different amounts of light for photosynthesis. 

Here are a few plants that are great for your Koi pond and will provide fish with shade from the sun, protection from predators, and will also provide an essential form of filtration by removing excess nitrates from the water.

Floating Plants

Water Lettuce: This is a true free-floating aquatic plant. Also called Shell Flower, it looks like a floating head of lettuce or cabbage with foliage that is ribbed and velvety. Its light green color makes a nice color contrast in your pond. 
This plant will also develop an impressive feathery root system that assists in natural filtration while providing valuable shade. These roots also inhibit algae growth by helping remove excess nutrients. 
The roots are also key to providing spawning habitat for your fish.Water Lily: Water lilies are rooted in soil in bodies of water, they should be potted and placed to the bottom of the pond.
The leaves and flowers will float to the surface and rise above the surface as they grow. 
The leaves are round and of different colors.Lily Pads: These plants benefit their habitats by providing shelter for fish and shade to keep the water cool. Water lilies provide safe spaces for frogs to perch on their leaves, hiding from underwater predators. 
Lilies also produce natural oxygen that allows fish to breathe and beneficial bacteria to thrive.

Submerged Plants

American Waterweed: Also known as Elodea, this plant does best in sunny areas of the pond. It lives entirely underwater with the exception of small white flowers that bloom at the surface and are attached to the plant by delicate stalks. This species also provides the ideal location for Koi egg-laying.Fanwort: Just like Elodea, is a plant that requires direct sunlight and grows extremely fast. It is favored by aquarists as an ornamental and oxygenating plant for fish. The darker green stems branch off into thin needle-like leaves this plant is the perfect habitat for the Koi to lay their eggs.

ESSENTIAL EQUIPMENT FOR YOUR POND

Filter

The filter is the heart of your Koi pond. The filter is what keeps the water clarity good and healthy for the fish.

Many pond owners have failed because they spent all their money on a beautiful pond and tried to save money on their filter. The filter serves two purposes. 

One, it serves as a mechanical filter removing fish waste and anything else in the pond that would cloud the water. 

Two, it serves as a biological filter by converting the ammonia produced by the fish into nitrites and eventually into nitrates which, in general, are harmless to the fish. 

Oxygen for the Koi Pond is provided by an aeration system, and the water is pumped with an external pump. No high voltage electrical devices are in the water.

Overfeeding and overstocking, especially while the biological filter is still maturing, are the most common causes of water-quality issues in koi ponds, so be careful.

Filters are needed to remove dirt as well as plant and fish waste from the water. However, the main role of the filter is the media which provides surface an area for beneficial bacteria to grow.

The water which passes through the filter keeps these bacteria well oxygenated. Some of the bacteria play a key role in the conversion of ammonia to nitrites which are then turned into nitrates by a different kind of bacteria.

These nitrates are then absorbed by plants which complete the nitrogen cycle.

Pump

There are two different types of pumps that can be used in a pond system. The first is an air pump that has the tubing connected to it with an air stone that should be placed into the water.

This pump provides aeration to the pond and will increase the amount of dissolved oxygen which is necessary for the respiration of both plants and fish.

The second type of pump is a water pump. This kind takes water from one end of the pond to a feature like a waterfall or a stream and therefore creates a continuous water flow and gives the pond a more natural feel.Be sure the pump has enough power for the size of your pond. 
All ponds and waterfalls need a circulating pump. These come in many different sizes according to how high you need to pump the water and how fast you want the flow rate. 
The pump will need to be placed in the pond, but it needs to be off the bottom of the pond floor by an inch or two. This keeps the pump from sucking up sediment.

Heater

A pond heater is a heater that warms the water of the pond to the regulated temperature which in the case of Koi should be between 55-77F.

Temperature is extremely important within aquaculture because fish are ectotherms which means they can’t regulate their body temperature.

This can therefore impact their growth and health.

The three most popular heaters which work well for Koi ponds are deicers, inline electric water heaters, and gas-fired boilers.

Which one you choose will depend on the size of the pond and your budget. Aquarium heaters will also work well for small indoor ponds.

Minimizing dissolved pollutants and maintaining a constant pH level aren’t the only water quality issues you will face; you must also ensure that your water is at the correct temperature. A water heating system is preferable for koi, but it may not be essential. If you live in a cold region, the koi will hibernate underneath surface ice if necessary. They can live in this fashion for several months, but it is not their preferred way of living, so you should seriously consider a water-heating system that will maintain the pond at more ideal temperatures for the koi’s well-being and growth.

Summary

Koi are among the most graceful and attractive fish to keep. Koi keeping has been popular for hundreds of years and is still growing.

Koi can be expensive fish because of their bright colors, but they reproduce quickly.

Feed the koi specialty pellets regularly and treat any health problems that arise. Maintain the water quality in the pond and keep it clean, so that the koi stay happy and healthy.

With the Koi, you can also keep different species of fish like Plecostomus which help the Koi to keep your pond clean and control algae.

Koi live for around 15 to 20 years and are ideal companions that you can lovingly nurture.