How to Build and Maintain a Koi Pond In Charlotte

Learn everything you need to know about building and maintaining koi ponds.

A koi pond can be an attractive feature in any backyard. 

Building and maintaining koi ponds are fun and rewarding activities, but they aren’t always easy. Learning about how to care for your pond and fish is necessary to make your pond construction a success.

At Charlotte Backyard Ponds, we’re happy to help with any of your pond needs. Before building a koi pond in Charlotte, North Carolina, there are a few things to consider.

Father and son enjoying a koi pond

Before Building Your Koi Pond

Firstly, pond construction and maintenance are time-consuming endeavors. While koi fish are elegant creatures, they require a great deal of attention. Keeping your fish healthy will cost you both time and money.

Another thing to remember is that converting your pre-existing backyard pond usually won’t work. Koi require specific conditions to thrive, which means a healthy pond begins at construction. There are cheaper options, which we’ll discuss more below, but it is generally best to build a koi pond from scratch.

Draw up a Blueprint

To ensure that your koi pond will function properly, you need a blueprint before starting construction. Going in blind could prevent your koi from thriving.

Budget and materials: As your blueprint is drawn up, consider your budget to determine what materials you will use. You will need to choose between options like fiberglass-finished concrete or a rubber pond liner.

Size: Start by deciding how large of a pond you want to build. At a minimum, koi ponds require at least 1,000 gallons of water—at three feet deep, that’s six by eight feet wide. Of course, if you intend to introduce more fish over time, you should start with a larger pond.

Climate: At this point, you should also consider the climate you live in. Koi fish can survive with a thin layer of ice at the top of the pond, but the air still needs to interact with the water. In colder climates, water features like fountains or waterfalls are excellent options to ensure the pond water stays aerated.

While the cold is less of a concern in Charlotte, North Carolina, it is still important to consider how the climate may impact the variety of koi in your pond.

Construct Your Koi Pond

With your blueprint complete, it’s time to get started on constructing your koi pond. By now, you should have an idea of how many fish you’ll need to accommodate and exactly where you’d like to build your pond.

Construct your pond to prevent “dead spots”—areas of the pond where water is stagnant. Experts recommend fiberglass-treated concrete to achieve the best water circulation. This keeps the water oxygenated throughout the pond, maintaining a healthy pH balance and thriving koi.

In place of concrete finished with fiberglass, a cheaper option is to use a rubber liner. Keep in mind, however, that this cost-reducing option also requires additional attention for proper maintenance.

While it may be one of the last things to cross your mind, your koi pond will also need some kind of protection for the fish. Predatory birds and mammals may threaten your fish without a protective barrier. Covering your pond with a safety net will keep natural predators away.

Healthy koi fish swimming in backyard pond

Maintain Your Koi Pond

It is easier to keep a koi pond clean with the proper construction. As mentioned above, many design aspects help maintain pond water. Regardless, there are still multiple steps to keeping a pond clean.

Water Quality

It is essential to maintain the quality of water in your koi pond. The pH level should be between 7.0 and 8.0. Anything over 8.0 may result in alkalosis, and anything below 7.0 may cause acidosis. Both conditions can harm your fish.

Maintaining appropriate ammonia, nitrite, and nitrate levels is also essential. Keep nitrite and ammonia levels as close to 0 as possible, while nitrate should remain below 50 parts per million. These levels may rise and fall naturally, so monitoring them closely is essential.

Invest in a water test kit to ensure that the water quality of your pond remains habitable. These kits examine the chemical levels of your pond’s water, indicating what maintenance you may have to perform.


Another essential feature to keeping your pond clean is a quality filtration method. Much like an indoor aquarium, it is important to filter water to keep it clean and oxygenated.

There are many natural filtration methods. Beneficial bacteria naturally occurring in the water convert ammonia and nitrite into nitrate. Furthermore, constructional designs that provide settling chambers push larger debris to areas easily accessed for cleaning.

You should also employ a mechanical filter regardless of which filtration method you choose. You will place these devices directly in the path of water flow to catch debris. Many experts recommend cylindrical brushes in at least four rows.

man feeding his koi fish

Keep Your Koi Fish Healthy

Keeping the pond water clean is not enough to help your koi fish stay healthy. The well-being of the fish depends on myriad other factors, too.

Be sure to avoid overcrowding in your pond; maintaining a healthy population for the size of your pond helps prevent a buildup of waste. As a general rule, a fish needs at least 10 gallons of water for each inch of body length. Remember, koi fish continue to grow throughout their life, so you’ll need to have enough space to keep the fish healthy as they grow.

Additionally, providing your koi with a balanced diet is essential to your fish’s health. While koi will eat any bugs or algae occurring naturally in their environment, you should supplement their diet with food containing quality proteins, vitamins, and probiotics. Feed your fish once per day in the colder fall and winter months and twice per day during summer.

Professional Pond Experts in Charlotte, North Carolina

Though building and maintaining a koi pond is doable on your own in Charlotte, North Carolina, it’s always best to consult with a professional. At Charlotte Backyard Ponds, we have the tools and know-how to help you create the perfect pond for your space. From construction to repair to maintenance, we’re happy to assist in every step of the process. Fill out our online form to tell us about your koi pond project, or give us a call directly at (704) 271-5234 to get started.