In 2017, HCity Farm built a pilot farm in Oita prefecture, Japan. On 3,000m2 premises, three separate facilities have been built and connected through underground circulated pipes system. The 1,000m2 main building contains the Closed Indoor Aquaponics, and VegilabTM laboratory, and some office spaces. This facility is built to completely control the plant growth environment such as temperature, humidity, CO2 level, LED lights and more. The aquaculture facility separate from the main building has 4 fish tanks and 1 large filtration structure, which is equipped with state-of-the-art systems. Currently, 4 fish tanks are used to grow rainbow trout under different conditions. A greenhouse which is approximately 1000m2 was built to practice aquaponics and hydroponics under semi-controlled conditions. And we are accumulating data that can be used for the next generation through daily accumulation.

What's Aquaponics?

“Aquaponics” is a new agricultural system which combines conventional aquaculture with hydroponics in a symbiotic environment. With aquaponics, one can grow high quality vegetables, fruit, and fish in a controlled environment, all while minimizing consumption of energy and water. The concept was first introduced almost 40 years ago in United States. Since then, R&D efforts have been taking place at many research institutions and some enterprises have successfully adapted aquaponics systems at the commercial level. It is an emerging sustainable agricultural model that is also of interest to Australia, Africa, and Europe.

Aquaponics Mechanism

This illustrates the symbiotic relationships in an aquaponics system. Aquaponics works because it’s an ecosystem approach to agriculture. Once the fish are fed, they excrete ammonia, which becomes dissolved in the water.

Nitrifying bacteria, which are purposely cultivated in the aquaponics system, then metabolize this ammonia. These nitrifying bacteria convert the ammonia to nitrite and then nitrate, which essentially is plant food. This nitrate-laden water is then moved to the hydroponic component of the aquaponics system, where the plants uptake and remove the nitrate from the water, thus cleaning the water for the fish. The cleaned water then goes back to the fish tank.

Suitable Environment

Aquaponics and USDA organic certificate

Aquaponics mimics the natural dynamics of soil and water in the environment. The fertilizer in an aquaponics system comes from the fish waste. Without the use of chemical fertilizers and pesticides, it is the only organic hydroponic method that has proven itself to be commercially viable. Aquaponics can be urban agriculture since it doesn’t require extensive land or soil, and the system can be flexibly installed in limited space in the city. This creates a system of ‘Farm-To-Table’, where city-dwellers have access to fresh, local vegetables.

Aquaponics & Organic

Hcity Farm has developed its own commercially-available Aquaponics system, which has obtained organic farming certification from United States Department of Agriculture.


Vegilab? is a laboratory system operated by Hcity Farm withthe collaboration of Diagenetix, Inc. USA.

Vegilab? focuses on research & development in food safety,tissue culturing technology, and crop disease diagnostics to establish better agriculture technologies and practices.

Kinomo 41-1, Ajimu-machi, Usa-city,
Oita 872-0507