Newbean Capital LLC describes indoor agriculture as ‘the practice of growing in warehouses, containers and greenhouses using hydroponic, aquaponic, and aeroponic techniques’.
Aquaponics refers to any system that combines conventional aquaculture (raising aquatic animals such as snails, fish, crayfish or prawns in tanks) with hydroponics (cultivating plants in water) in a symbiotic environment. In normal aquaculture, excretions from the animals being raised can accumulate in the water, increasing toxicity. In an aquaponic system, water from an aquaculture system is fed to a hydroponic system where the by-products are broken down by nitrifying bacteria initially into nitrites and subsequently into nitrates, which are utilized by the plants as nutrients, and the water is then recirculated back to the aquaculture system. Aquaponic systems do not typically discharge or exchange water under normal operation, but instead recirculate and reuse water very effectively. The system relies on the relationship between the animals and the plants to maintain a stable aquatic environment that experiences a minimum of fluctuation in ambient nutrient and oxygen levels. Water is added only to replace water loss from absorption and transpiration by plants, evaporation into the air from surface water, overflow from the system from rainfall (if outdoors), and removal of biomass such as settled solid wastes from the system. As a result, aquaponics uses approximately 5% of the water that a conventionally irrigated farm requires for the same vegetable production. Also, because there is no soil used, there is no chance for soil-borne diseases. There will be less harm caused by insects and no need for weeding or herbicides.
Hydroponics is a method of growing plants without soil, by using mineral nutrient solutions in an aqueous solvent. Terrestrial plants may be grown with only their roots exposed to the nutritious liquid, or, in addition, the roots may be physically supported by an inert medium such as perlite, gravel, or other substrates.
Plants commonly grown hydroponically, on inert media, include tomatoes, peppers, cucumbers, strawberries, lettuces, marijuana, and model plants for research purposes.
Hydroponics offers many advantages, one of them being a decrease in water usage for agriculture. To grow 1 kilogram (2.2 lb) of tomatoes using intensive farming methods requires 400 liters (88 imp gal; 110 U.S. gal) of water; using hydroponics, 70 liters (15 imp gal; 18 U.S. gal); and only 20 liters (4.4 imp gal; 5.3 U.S. gal) using aeroponics. Since it takes much less water to grow produce, it could be possible in the future for providers in harsh environments with little accessible water to grow their own food.