Spectra of all discs considered in this study. The fluxes have been rescaled with respect to distance and $L_{\text{acc}}^{0.6}$, the full discs are arranged from largest ${\text{H}}_2{\text{O}}_{\text{cold}}/L_{\text{acc}}^{0.6}$ (bottom), to smallest (top). The right column shows sections of the spectra with C₂H₂ (yellow shading) and HCN (orange shading) emission (top), and H₂O (blue shading) emission (bottom). The triangle in the bottom right panel indicates the line in this wavelength region used to calculate the cold H₂O flux. The shaded regions of C₂H₂ and HCN are also the regions over which the integrated fluxes are calculated.