Making aquaponics a business: A framework

Commercial aquaponics systems remain a challenge independent of the country, fish, plant species, or system design type. Most aquaponics systems are made by hobbyists, with aquaponics not being the main source of income. As such, scholars and practitioners have long debated the real profitability of aquaponics systems. With the growth of the aquaponics industry and commercial businesses, sustainable economic viability is necessary. Recently, considerable literature has been published around the theme of aquaponics systems design but there is a gap in the literature regarding the business aspect of this. Moreover, only by acquiring the enterprise knowledge of planning a business case, obtaining funds, and running and maintaining a business will this industry be able to grow. This paper intends to create a directory of possible considerations to plan for a viable commercial aquaponics system by uniting already established business frameworks and adapting them to the aquaponics industry. This framework proposes a guide to evaluate the economic feasibility of the enterprise depending on the revenues, costs and investments needed for the chosen system within its operations, market, and environment.publishedVersio

Carbon dynamics and energy recovery in a novel near-zero waste aquaponics system with onsite anaerobic treatment

Aquaponics is gaining renewed interest to enhance food security. This study aimed to investigate the performance of a novel off-grid aquaponics system with near-zero water and waste discharge, focusing on the carbon cycle and energy recovery that was achieved by the addition of onsite anaerobic treatment of the solid waste streams. Following a stabilization stage, the system was closely monitored for four months. Fish tank water was recirculated via solid and nitrification reactors, from which 66% was recycled to the fish tank directly and 34% indirectly through the hydroponically grown plants. Fish solid waste was anaerobically treated, energy was recovered, and the nutrient-rich supernatant was recycled to the plants to enhance production. Plant waste was also digested anaerobically for further recovery of energy and nutrients. Fish stocking density was 15.3 and over time reached approximately 40 kg/m3 where it was maintained. Feed (45% protein content) was applied daily at 2% of body weight. Typical fish performance was observed with a survival rate >97% and feed conversion ratio of 1.33. Lettuce production was up to 5.65 kg/m2, significantly higher than previous reports, largely because of high nutrients reuse efficiency from the anaerobic supernatant that contained 130 and 34 mg/L N and P, respectively. Of the feed carbon, 24.5% was taken up by fish biomass. Fish solid wastes contained 38.2% carbon, of which 91.9% was recovered as biogas (74.5% CH4). Biogas production was 0.84 m3/kg for fish sludge and 0.67 m3/kg for dry plant material. CO2 sequestration was 1.4 higher than the feed carbon, which reduced the system's carbon footprint by 64%. This study is the first to demonstrate highly efficient fish and plant production with near-zero water and waste discharge and with energy recovery that can potentially supply the system's energy demand.publishedVersio

Navigating towards decoupled aquaponic systems : a system dynamics design approach

The classical working principle of aquaponics is to provide nutrient-rich aquacultural water to a hydroponic plant culture unit, which in turn depurates the water that is returned to the aquaculture tanks. A known drawback is that a compromise away from optimal growing conditions for plants and fish must be achieved to produce both crops and fish in the same environmental conditions. The objective of this study was to develop a theoretical concept of a decoupled aquaponic system (DAPS), and predict water, nutrient (N and P), fish, sludge, and plant levels. This has been approached by developing a dynamic aquaponic system model, using inputs from data found in literature covering the fields of aquaculture, hydroponics, and sludge treatment. The outputs from the model showed the dependency of aquacultural water quality on the hydroponic evapotranspiration rate. This result can be explained by the fact that DAPS is based on one-way flows. These one-way flows results in accumulations of remineralized nutrients in the hydroponic component ensuring optimal conditions for the plants. The study also suggests to size the cultivation area based on P availability in the hydroponic component as P is an exhaustible resource and has been identified one of the main limiting factors for plant growth

The aquaponic principle—It is all about coupling

The aquaponic principle is the coupling of animal aquaculture (e.g. fish) with plant production (e.g. vegetables) for saving resources. At present, various definitions of aquaponics exist, some bearing the risk of misinterpretation by dismissing the original meaning or being contradictory. In addition, there is no standard terminology for the aspects of coupling between the aquaponic subsystems. In this study, we addressed both issues. (1) We developed new or revised definitions that are summarised by: Aquaponic farming comprises aquaponics (which couples tank‐based animal aquaculture with hydroponics) and trans‐aquaponics, which extends aquaponics to tankless aquaculture as well as non‐hydroponics plant cultivation methods. Within our conceptual system, the term aquaponics corresponds to the definitions of FAO and EU. (2) A system analysis approach was utilised to explore different aquaponic setups aiming to better describe the way aquaponic subsystems are connected. We introduced the new terms ‘coupling type’ and ‘coupling degree’, where the former qualitatively characterises the water‐mediated connections of aquaponic subsystems. A system with on‐demand nutrient water supply for the independent operating plant cultivation is an ‘on‐demand coupled system’ and we propose to deprecate the counterintuitive term ‘decoupled system’ for this coupling type. The coupling degree comprises a set of parameters to quantitatively determine the coupling's efficiency of internal streams, for example, water and nutrients. This new framework forms a basis for improved communication, provides a uniform metric for comparing aquaponic facilities, and offers criteria for facility optimisation. In future system descriptions, it will simplify evaluation of the coupling's contribution to sustainability of aquaponics.Belmont ForumEuropean Commission via the CITYFOOD projectPeer Reviewe

The aquaponic principle : it is all about coupling

The aquaponic principle is the coupling of animal aquaculture (e.g. fish) with plant production (e.g. vegetables) for saving resources. At present, various definitions of aquaponics exist, some bearing the risk of misinterpretation by dismissing the original meaning or being contradictory. In addition, there is no standard terminology for the aspects of coupling between the aquaponic subsystems. In this study, we addressed both issues. (1) We developed new or revised definitions that are summarised by: Aquaponic farming comprises aquaponics (which couples tank-based animal aquaculture with hydroponics) and trans-aquaponics, which extends aquaponics to tankless aquaculture as well as non-hydroponics plant cultivation methods. Within our conceptual system, the term aquaponics corresponds to the definitions of FAO and EU. (2) A system analysis approach was utilised to explore different aquaponic setups aiming to better describe the way aquaponic subsystems are connected. We introduced the new terms ‘coupling type’ and ‘coupling degree’, where the former qualitatively characterises the water-mediated connections of aquaponic subsystems. A system with on-demand nutrient water supply for the independent operating plant cultivation is an ‘on-demand coupled system’ and we propose to deprecate the counterintuitive term ‘decoupled system’ for this coupling type. The coupling degree comprises a set of parameters to quantitatively determine the coupling's efficiency of internal streams, for example, water and nutrients. This new framework forms a basis for improved communication, provides a uniform metric for comparing aquaponic facilities, and offers criteria for facility optimisation. In future system descriptions, it will simplify evaluation of the coupling's contribution to sustainability of aquaponics

Vitamin D3 and K2 and their potential contribution to reducing the COVID-19 mortality rate

The world is desperately seeking for a sustainable solution to combat the coronavirus strain SARS-CoV-2 (COVID-19). Recent research indicated that optimizing Vitamin D blood levels could offer a solution approach that promises a heavily reduced fatality rate as well as solving the public health problem of counteracting the general vitamin D deficiency. This paper dived into the immunoregulatory effects of supplementing Vitamin D3 by elaborating a causal loop diagram. Together with D3, vitamin K2 and magnesium should be supplemented to prevent long-term health risks. Follow up clinical randomized trials are required to verify the current circumstantial evidence

A fully integrated simulation model of multi-loop aquaponics : A case study for system sizing in different environments

Decoupled multi-loop aquaponics systems separate the recirculated aquaculture system (RAS) and hydroponic (HP) units from each another, creating detached ecosystems with inherent advantages for both plants and fish. This gives the advantage of improved crop and fish cultivation in combination, using the minimum resource input. Up to today, the focus of aquaponics systems is mainly on fish culture and treatment of RAS effluent for optimal use in HP, and systems are designed and sized with rule of thumbs of plant growth, evapotranspiration and nutrient needs, while taking the slow responses of RAS dynamics as basis. However, in order to create the optimal fit between RAS and HP, the different systems and differences in time responses of the underlying process need to be considered. Growth of fish and plants happen in hours or days and are slow processes while photosynthesis and transpiration in crops happen in seconds or minutes and are fast processes. As in a closed loop system the main water use is due to plant transpiration, the necessary sizes of system and sub-system depend on plant transpiration. We therefore aimed at creating an aquaponics-sizing simulator based on deterministic mathematical models and thus transferrable to various circumstances with simple parameterisation. We have combined a full-scale greenhouse simulator with a possible simulation time of min 1 min including HP, greenhouse construction and physics as well as a very detailed plant energy and growth model with a model for a multi-loop aquaponics system including distillation technologies and sumps. To illustrate the quality and wide applicability of our theoretical implementation of a multi-loop aquaponics system in greenhouse conditions we made scenario simulation studies at three different climate zones as sub-arctic cold, moderate and arid subtropical regions (i.e. Faroe Islands [66°N], The Netherlands [52°N], and Namibia [22.6°S]) using the same RAS size while simulating on the fitting HP area. For sizing, we used the element P as the most valuable macronutrient for plants. We simulated in a 1-min time steps for a 3-year duration using hourly input climate data for a complete year. Results clearly indicate the importance of transpiration dynamics on system and sub-system sizing, where e.g. the optimal HP size necessary was 11,250 m 2 , 10,250 m 2 and 5250 m 2 (tomato), or 15,750 m 2 , 14,000 m 2 and 9250 m 2 (lettuce), for Faroe Islands, The Netherlands, and Namibia, respectively. </p

The necessity of desalination technology for designing and sizing multi-loop aquaponics systems

Providing both fish and plants with optimal environmental conditions is a classical problem in the field of aquaponics. Several studies have tackled this problem by decoupling fish and plant systems. However, in order to achieve both high nutrient levels for the plants and low nutrient and particulate loading in the fish tanks, suspended matter in the aquaculture component needs to be discharged and fertilizer needs to be added to the plants continuously. The present study aims to explore to what degree desalination technology could potentially be used to provide the necessary balance between the two different components based on a theoretical modelling approach using contemporary source material. We suggest how specific desalination engineering approaches can improve the nutrient balances in multi-loop aquaponics systems in order to attain optimal growth conditions for both fish and plants