21.2 Classification of Controlled Environment Aquaponics

The term aquaponics is used to describe a wide range of different systems and operations, greatly varying in size, technology level, enclosure type, main purpose, and geographic context (Junge et al. 2017). The first version of the classification criteria for aquaponic farms included stakeholder objectives, tank volume, and parameters describing aquaculture and hydroponic system components (Maucieri

img src="https://cdn.aquaponics.ai/thumbnails/c7770dc3-ea11-4f37-94b9-64f54d9a1d1e.jpg" style="zoom:48%;" /

Fig. 21.3 Classification criteria for identifying aquaponic farm types

et al. 2018). Additional work was undertaken by a large group of researchers to further define aquaponics and to present a nomenclature based on international consensus (Palm et al. 2018). This led to a comprehensive discussion on system types and scales and most importantly a definition of aquaponics which is: "the majority (> 50%) of nutrients sustaining the optimal plant growth must derive from waste originating from feeding the aquatic organisms." However, both definitions focus on the growing systems and do not consider other essential aspects of a functioning commercial aquaponics farm. As aquaponic operations become part of local economies, classification criteria identified by interdisciplinary research in fields like architecture, economics, and sociology will also become essential.

This classification proposal focuses on the emerging field of commercial aquaponic operations through the lens of the built environment. The key characteristics that describe an aquaponic operation fall into four different categories: growing system, enclosure, operation, and context (Fig. 21.3). These categories for classification criteria impact one other across scales, where growing system configurations can affect the contextual performance of the farm as a business, or local market demands can determine the type of crop grown in the aquaponic system. Some farm classification criteria are relevant on all scales, such as "size," measured in tank volume, growing area, number of employees, and annual revenue (Table 21.1).

• Growing system classification criteria describe the configuration of the interconnected aquaculture and hydroponic system. This includes specifications for the physical components that enable water and nutrient recirculation (such as water tanks, filters, pumps, and piping), living organisms that transform available nutrients at different stages (including fish, plant, and microorganism species) and values describing the physical performance of the system, such as temperature, pH levels, oxygen/carbon content, and electrical conductivity (Alsanius et al. 2017).

Table 21.1 Possible classification criteria for aquaponic farm types

table thead tr class="header" thGrowing system/th th Enclosure /th th Operation /th th Context /th /tr /thead tbody tr class="odd" tdAquaculture system type/td td Enclosure typology /td td Purpose /td td Geographical location /td /tr tr class="even" tdFish species/td td Structural system /td td Stakeholders /td td Physical context /td /tr tr class="odd" tdWater temperature/td td Envelope assembly cover material /td td Business model /td td Environmental impact /td /tr tr class="even" tdFiltration system/td td Heating/cooling systems /td td Labor distribution /td td Socioeconomic context /td /tr tr class="odd" tdFeed type/td td Light source /td td Funding type /td td rowspan=4 Social impact /td /tr tr class="even" tdHydroponic system type/td td Ventilation system /td td Marketing scheme /td /tr tr class="odd" tdCrop species/td td rowspan=2 Host building integration /td td rowspan=2 Distribution model /td /tr tr class="even" tdWater distribution system/td /tr /tbody /table

• Enclosure classification criteria define characteristics of the buildings that house the growing systems, at the next scale. Most aquaponic farms use CEA enclosures that vary by identifying typology (such as a greenhouse or warehouse), structural system, heating and cooling systems, lighting, ventilation, and humidity control systems (Benke and Tomkins 2017).
• Operations classification criteria describe how each aquaponic farm operates as a business and farm, which includes human expertise and labor input necessary for growing and selling produce. Criteria in this section include funding type, business structure and management, labor requirements and division, marketing scheme, produce distribution model, and overall purpose of the aquaponics facility.
• Context classification criteria, at the largest scale, describe the geographic location, physical context, urban integration, and overall social impact of aquaponic farms. Context criteria describe how an aquaponic farm is part of the urban food chain and built environment, capable of influencing economic growth, social involvement and large-scale environmental impacts on a city-wide scale (dos Santos 2016).