Nonlinear Auto-Regressive with Exogenous Inputs (NARX) Modelling of Hydroponics Water pH Level in response to Acid and Alkaline Solutions

Nutrients are essential to optimising plant growth. However, the introduction of fertiliser in a hydroponics setup influences pH level nutrient solution. This, turn, could affect plants' growth as many types plants require specific range grow optimally. Conventional cultivation performs adjustment manually – meticulous and error-prone process. Manual solutions is prone estimation errors, particularly when levels change drastically due slow response solution addition alkaline or acidic mixtures sensitivity minute errors mixture delivery. For these reasons, model estimate solution's would help improve delivery accuracy mixtures. Past research offers minimal study optimally construct from System Identification (SI) perspective. This represents water neutralisation behaviour using Nonlinear Autoregressive with Exogeneous Inputs (NARX). The project begins input output data acquisition, leading development NARX model. Model performance was then evaluated by analysing fit residual distribution.