pothos growing in aquarium

As the temperatures get colder and gardening work outside slows down, you might be looking for a plant growing project to do inside. I encourage you to try aquarium aquaponics.

There is a natural mutually beneficial relationship between plants and aquatic animals such as fish. The fish are making waste that is high in nitrogen and other nutrients. Nitrogen levels can become toxic to the fish if it is not removed from the water. 

This is where the plants come in. The plants take up the nitrogen compounds and use it for green, leafy growth which keeps the water safe for the fish. 

Keeping the water circulating is very important. The roots still need oxygen to keep them healthy. The roots will be susceptible to pathogens in water with low oxygen levels.  Filters and aerating bubblers for a typical aquarium are enough to provide required oxygen levels. 

A fluorescent light is above the system to provide the necessary light for the plants to thrive. I recommend putting the light on a timer to keep a light/dark cycle for the plants and fish. 

A support system was created to keep the plants at the right level at the top of the aquarium. In this system a light-weight plastic top was created that lets light through and keeps the plants at the right level. The plastic piece sits on the top of the aquarium. Holes were cut in the plastic to allow the pots to be in the water. 

Small pebbles are used to anchor the plants in the pots instead of soil. Using pebbles keeps soil debris out of the aquarium. Pebbles used for aquariums work well for this.

In this system, pothos plants are thriving. Herbs also work well in this type of system. Producing flowers may be difficult in this system due to the level of nitrogen available to the plant. 

Once the plants are in place, enjoy observing the ecosystem you have created.