Koi Pond Aquaponics


Our DIY backyard koi pond aquaponics set up is, well, set up. We decided to go with koi instead of the commonly used tilapia for several reasons. Allison doesn’t like getting rid of something once she’s named it, and tilapia isn’t our favorite fish to eat, and since we aren’t raising them for food, why not have the beauty of koi?

It holds roughly 250 gallons and is made from cinder blocks, a 10’x12′ 20mil Pond liner, with underlay, but turned out to be to harsh. We decided instead to wrap it in landscape timbers.

DIY Koi Pond Aquaponics

Aquaponics is basically growing plants with fish waste. Fish put off ammonia, a bacteria converts ammonia into Nitrite, a second bacteria converts Nitrite into Nitrate. Nitrate is not harmful to fish and is used as nutrition by the plants. Neither Allison or myself have ever had a pond or grown anything via aquaponics so we were excited to tackle a new project.

We ordered this pretty powerful pump on Amazon because you can always cut the flow down with valves, and being in Florida water aeration is going to be critical in the heat. We will be running everything with 3/4 PVC, split between a waterfall, the grow beds and eventually a swirl filter as we add koi.

The grow beds are cement mixing tubs from Home Depot that hold 21 gallons, filled with lava rock and pea gravel. After they are full they flood and drain about 5 gallons of water per cycle. I ordered some 3/4″ bulkheads from Amazon and drilled the bottoms to set up the bell siphons.

We have several other aquariums that we took some filter media out of and added to the pond so we could add fish pretty much right away. We started with 5 goldfish for several weeks while the seeds germinated and started growing. I wanted to keep a balance of waste and plant growth, especially in the beginning.

Here is a quick video of our DIY Koi Pond aquaponics system in operation in the beginning.

There are a number of changes that we will be working on in the future including replacing the filter bucket with a waterfall that will sit on the three block across the back, adding a sump, a swirl filter, and another grow bed or two.