e \cite{Asciuto_2019}. While about investment measures there
are various programs such as Urban Innovative Actions \cite{uia}, Milan Urban Food
Policy Pact \cite{pact}and Reinventing Cities \cite{cities}. In addition, it is worth mentioning
the action plan of the European Green Deal in which urban agriculture is
an integral part \cite{europeo}.
As regards the progress of research on the aquaponic system, emerges an
interesting study proposed by Pérez-Urrestarazu et al. \cite{P_rez_Urrestarazu_2019} on the
optimization of small-scale aquaponic systems of FAO models by analysing
the different hydroponic subsystems (nutrient film technique - NFT,
floating raft - DWC and vertical felt) and tested to produce lettuce and
goldfish. The three systems showed different results related to fish and
lettuce yield, water consumption and nitrate accumulation. Alongside
this research, the study by Ong et al. \cite{Jie_Ong_2019}demonstrates the opportunity in
the use of IoT technologies that allow you to monitor the remote
operating parameters of the aquaponic system, offering the potential to
improve food safety and sustainability, with a reduction in manpower and
operating costs.