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10 Amazing Indoor Koi Pond Ideas for Your Home (With Pictures)

Grant Piper

By Grant Piper

koi fish pond

As people spend more and more time at home, they are looking to turn their house into a place of serenity. One way to add calmness and style to a space is by adding an indoor koi pond. Indoor koi ponds come in all different shapes and sizes and can be designed to hold one koi fish or dozens. If you do not know where to start with an indoor koi pond, you have come to the right place. This list features 10 amazing indoor koi pond ideas for your home. Each idea is unique, viable, and versatile. By the end, your head will be swimming with possibilities for your very own indoor koi pond.

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The 10 Amazing Indoor Koi Pond Ideas for Your Home

1. Indoor Stock Tank Koi Pond

Stock tanks are large, durable, and watertight which makes them a great base for an indoor koi pond. If you can get a large stock tank into an indoor space, you can make your very own koi enclosure with it. Simply add a filtration system, add some koi friendly plants, and finally, add your koi fish. Do note that full sized koi fish will not be able to live in a stock tank long term. Stock tanks are large enough for a couple of small koi or for young and adolescent koi fish. But your koi fish might outgrow your stock tank after a few years of happy living.

2. Small Container Koi Pond

mini koi pond
Image Credit: fishkeepingforever

This small container koi pond can be built to permanently house goldfish or very small koi fish. It is the perfect addition to a sunroom or living room. This idea gives you the essence of a full-sized koi pond, but it is distilled down to a more manageable size. You can decorate this container with whatever rocks or plants you desire. It would also look great next to some bonsai trees to really hammer home the miniature vibe. This idea is perfect for small houses or small spaces looking for big Zen.

3. Water Trough Koi Pond

Large water troughs could make for the perfect indoor koi pond base. Some water troughs can hold enough water to house small or young koi fish, and they can look absolutely stunning while doing it. Water troughs come in a variety of different shapes and sizes. They are easy to move and are designed to sit with water in them full time. They can be painted or refinished to be different colors. They also look good with a fountain or bubbler attached. You do have to be careful about using galvanized metal troughs as the high zinc can potentially harm fish.

4. Repurposed Old Boat Pond

convert a boat
Image Credit: fishkeepingforever

You can also repurpose an old boat into a koi pond. Boats can make great ponds because they are already waterproof and can easily be made watertight. The size, shape, and type of boat that you have will determine how much water it can hold and how many koi fish it can potentially house. A bulky rowboat will hold more water than a slender kayak. Canoes are also another good option. Make sure that the shape, size, and style of the boat you have or are thinking of can fit into your indoor space.

5. Upcycled Hot Tub Koi Pond

hot tub pond
Image Credit: fishkeepingforever

Old hot tubs can be an eyesore and a bear to move. The good news is if you have an old or unused hot tub collecting algae in the backyard, you can convert it into a koi pond. Make sure the hot tub is still watertight and give it a good cleaning before trying to move it indoors. If you can reposition it, the hot tub can make for a versatile and effective koi pond base. Hot tubs are big enough for one to two koi fish but likely not more than that. The larger the hot tub, the more koi fish it can potentially hold.

6. Expansive Man Cave Koi Pond

If you are looking to go all out on your indoor koi pond, look no further. For the truly dedicated, truly skilled, or truly insane, you can build your very own aquarium grade koi pond right in the comfort of your man cave. That is exactly what one man did and created quite the buzz online. This tank is absolutely massive and can hold multiple full sized koi fish and proudly display them. This tank goes to show you that anything can be do-it-yourself if you put enough time, energy, and money into the project.

7. Modern Staircase Koi Pond

under stair koi pond design
Image Credit: homemydesign

One modern place to put a Zen indoor koi pond is under the stairs. In many homes, the area underneath a staircase can be dead space. Put that space to good use by installing a koi pond. That way, you can peer down at your happy koi fish while you are on the stairs. It will also fill the area around the stairs with a pleasant burbling sound. Pulling off an indoor koi fish pond under the stairs can be tricky, but with a good idea, previous experience, or professional help, it can be done with great results. This pond added mirrors to make the space look much bigger than it actually was and transformed the area under the stairs into a portal to an undersea world.

8. Indoor Shed Koi Pond

This man always wanted his own indoor koi pond. When none was forthcoming, he decided to build one himself. It took him five years and hours of backbreaking work, but the result is something truly unique and truly incredible. This koi pond looks professionally made and can fit dozens of adult koi. Anyone could spend hours reading, relaxing, and watching the koi fish from the comfort of this building. Building the pond its own outdoor house turned it from a basic hole in the ground to an indoor experience. It was not easy building a full indoor koi pond from scratch, but in the end, it was worth it.

9. Classic Sunroom Koi Pond

indoor koi pond
Image Credit: globalkoicenter

This koi pond is the classic indoor sunroom pond. Inspired by popular koi ponds in Asia, this pond takes the heart of a sunroom and completely takes it over. The result is a large and dominant pool that is able to hold multiple koi fish. This would be great for a koi enthusiast or for someone who likes to sit by the pond and meditate or relax. A pond of this nature will take the whole space around it and turn it into a koi room which can be great for someone going for a modern Asian aesthetic for their home. Such a large indoor koi pond will likely need professional workmanship in order to pull it off properly.

10. Simple Indoor Koi Pond

You can always upgrade your houseplant game with a simple indoor koi pond. This idea transforms a room already filled with your favorite greenery by adding a koi pond into the floor. This type of pond is great for sunrooms, greenhouses, and lanais. If you build it large enough or deep enough, you will have no trouble fitting multiple adult koi fish. Depending on your exact location, the type of floor you have, and the scope of the project, you might need to consult a professional for advice.

Mind the Water

A single koi fish requires 250 gallons of fresh water. Each koi fish you add needs a minimum of 200 gallons beyond that. Two koi fish need 500 gallons of water to be comfortable. Four koi fish need 1,000 gallons. That is a lot of water. Any time you add a water feature indoors, you need to be very careful. You have to ask yourself a number of questions. Is my pond or tank completely watertight? How am I going to fill the pond? Do I have a plan for draining it? What happens if I spring a leak or spill?

Running a hose into your house can be a risky prospect. If your pond leaks, will it destroy anything valuable? Can it damage the house? Bringing hundreds of gallons of water into your home should only be done with confidence and while knowing the risks that it entails.

Tips for Keeping an Indoor Koi Pond

Keeping an indoor koi pond can be tricky, especially for someone completely new to the koi game. While you can’t learn everything overnight, these tips can help steer you in the right direction and are important to know before you start any indoor koi pond project.

  • Don’t forget the filtration system.
  • Keep koi fish out of direct sunlight.
  • One koi fish requires 250 gallons of water. Each koi fish after that will require 200 additional gallons of water.
  • Try adding a bubbler or fountain to add volume and sound.
  • Consider adding koi-friendly plants for some greenery and texture.
  • Have a plan for a leak or spill.
  • Do not attempt to DIY a large koi pond without some serious research or experience.
  • Don’t be afraid to seek professional assistance for your project.
  • Make sure your koi pond or tank is large enough for your koi fish.


These 10 indoor koi pond ideas are sure to get your brain juices flowing. From stock tank ponds to elaborate indoor sunroom builds, there are projects here that are sure to kickstart your next koi pond adventure. Be aware that an indoor koi pond is not for the faint of heart. Koi require a lot of water, and the builds can be extensive and expensive. But the payoffs can also be massive and can transform a space into something completely unique and out of this world.

Featured Image Credit: ANI ROFIQAH, Shutterstock

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