Additive Manufacturing (AM) offers a range of possibilities in fluid flow research. An existing 2.5 m open channel fluid flow experiment contains a set of standard weirs which are limited in design. This research will compare experimental AM weirs (e.g. labyrinth, piano, catenary), that would not be possible on some laser-cut polymer or machined aluminium weirs. Due to the bespoke complex nature of weirs’ design other manufacturing methods would be too expensive and impossible to use. AM technology allows a cost-effective solution for progressive design modifications to be implemented throughout investigations. This paper will highlight comparisons made between a range of AM produced weirs in terms of flow rate, fluid velocity profile, water level height and discharge coefficient. Computation fluid dynamic modelling (CFD) will also be used to verify, analyse, and compare results. Based on the experimental results and verification, the paper will also discuss the suitability of application of AM techniques in fluid flow analysis.