Koi are one of the most popular fish used in aquaponics, and for good reason. Aquaponics with koi fish is often highly successful because these fish are well adapted to aquaponic setups. They have a long life span and easily live and breed within the system. This is because koi have long been kept in ponds, tanks, and the like for ornamental purposes. Relatives of the goldfish and the carp, they are also fairly disease and parasite resistant, which makes them very useful when kept in close quarters. These omnivorous fish will eat just about any food you give them. In many cases, additional feeding is not necessary because they will also eat algae, debris, and plant matter that fall into their pond. This does an excellent job of both reducing your feeding costs and keeping your pond clean.
A koi pond is also an ideal setup for backyard aquaponics. Using a koi pond for aquaponics allows you to add beauty to your backyard while growing organic food. The pond itself presents a unique visual addition, making it a focal point to backyard living. The koi also add beauty with their unique patterns, varied coloring, and large size. Watching the koi swim around in their pond can be peaceful and relaxing, but you also get the benefit of aquaponics with koi fish. Your pond will be so much more than an ornament to beautify your backyard. An aquaponics in ground pond in your backyard presents the opportunity to grow healthy, organic food that you can use or sell without the need for added fertilizers or specialty soil. Additionally, the koi are easy to sell when their breeding puts you into an overstock situation.
Koi Pond Design Considerations
Before getting started with a koi pond, you need to put some thought into the design. Because your pond will be used as a functioning aquaponic farm, several items require consideration. Some of the key considerations when you are designing a koi pond for aquaponics include:
• Regulations & Requirements – Local regulations, safety requirements, and even insurance requirements should be considered when adding an aquaponics in ground pond. There may be forms to fill out or fees to pay before you can even begin. This is true even if you plan on using a professional to install your pond. Check with your local zoning authorities, utility companies, and your insurance company before getting started.
• Location, Size, & Depth – Another important choice in koi pond design is where you want to put it and how big it will be. The location should be easy to access, allow enough space for all plumbing and electrical needs, and have enough room for the size and depth you choose. Keep in mind that larger ponds are easier to care for. Also, the colder your climate gets seasonally, the deeper your pond will need to be to protect the fish.
• Adding & Removing Water – Since your pond is outdoors, water levels may fluctuate more than they do in an indoor setup. Some koi pond maintenance will be involved in keeping water levels appropriate. In the hot season, water may evaporate more rapidly so your pond should be near a water source to make it easier to top it off. Additionally, you will need adequate drainage for rainy times when the pond floods. A means to completely drain and refill the pond is also important.
• Predators – When using a koi pond for aquaponics, you need to know what predators might come after your fish and your plants. This will vary based on your locality, but general tips for keeping predators out of your pond and garden include fencing, netting, and even pond covers. You can also look to use plants that will help to hide your koi from predatory birds.
• Normal Backyard Aquaponics Considerations – Your pond will soon be a thriving aquaponic system, but that also requires some consideration. You will require adequate aeration, appropriate time for the nitrogen cycle to occur, regular monitoring of pH and ammonia levels, and all the required parts like pumps, filters, and grow beds.
How to Build a Koi Pond
Another great aspect of a koi pond for aquaponics is that you can learn how to build a koi pond without needing a professional contractor. This will help reduce your startup costs and give you a real sense of accomplishment every time you see your pond. All you need is a carefully considered design, a few basic tools, the necessary materials, and this handy step-by-step guide to how I built my koi pond for aquaponics.
After choosing your location, the fun starts. It’s time to start digging. To maintain your chosen pond shape, you can use marking spray paint or you can lay the design out using rocks. The picture below shows my koi pond after the initial digging. This is a critical step in this process. Your pond sidewalls must be level in all directions. To achieve this, I packed the soil around the sidewalls to raise the sidewall slightly above the desired water level. Be sure to constantly check for level in all directions and adjust accordingly. I recycled old newspapers to help hold the shape of the sidewalls. Keeping the newspapers misted with water helped to compact the sidewall and form it’s final shape.
Also, for an outdoor koi pond you will need to decide on a spillway location, and include the spillway in your design. Be sure it overflows away from your main focal point. One final thought, be sure the pond bottom and walls are free of all debris, roots, rocks or anything that might puncture a hole in your pond liner.
Next, it’s time to start installing your pond liner. This is a critical stage in building a koi pond. Be prepared to get wet. After laying your pond liner in the pond, start adding water. As the water fills your pond, get in the pond, barefooted, to prevent the possibility of puncturing a hole in the liner. Start adjusting the liner to fit the hole. You will need to re-adjust many times as the pond fills and the pressure of the water pushes the liner into shape. You should end up with something like the picture below. Once you are happy with the positioning of the pond liner, go back and re-check the top sidewalls for level in all directions. Final step, trim any excess liner around the edges.
Now that you have your pond liner in place, and full of water, it’s time to start adding the trim of your choice around the pond. I chose to use rocks that are freely available on my property. There are many options that you can implement here, it all depends on the final look that you are after. I used concrete that I dyed with a charcoal color to install the first row of rocks around the pond. The rest are freely placed around the parameter of the pond to obtain my desired look.
After this step, you will need to pump all the water from the pond and rinse and clean, several times, before filling the pond again.
I recommend that you start your system by pumping the pond water through your aquaponic system for a few days before adding your fish. This is a picture of my koi pond for aquaponics, 20 months after building it. As you can see from the picture below, I later installed a waterfall and planted exotic plants around the pond. This is the final result.
Koi Pond Maintenance Tips
Once your koi pond for aquaponics is completed, stocked with koi fish, and properly setup to grow hydroponic plants, all your aquaponics system needs is a little routine maintenance. Establishing a maintenance routine is essential to the success of any aquaponics system, and it becomes especially important in an outdoor setup. Be sure you are regularly testing the water for pH, ammonia level, and temperature. This will help you notice variations that could become problematic before they harm your fish or plants. Frequently draining some of the water and adding fresh water will also help keep things balanced. Cleaning should occur on a routine basis as well to prevent algae overgrowth. Your fish will eat some of the algae, but you want to take steps to prevent an algae bloom. Checking and changing out filters, wiping down pond decorations like rocks, and monitoring algae levels are required.
As you can see, using a koi pond for aquaponics can be an easy and effective way to run a system that produces healthy, happy fish and plenty of organic plants to use for food or profit. By focusing on your design beforehand you can ensure you do not run into any surprises as you get started. Building the pond yourself is also possible, and will save you money. Finally, routine maintenance will keep aquaponics koi pond running smoothly year round.