Turbulent compositional flux ﹩| {\tilde{F}}_{C}| ﹩ is shown across a range of parameters against (a) the reduced density ratio (see Equation (3)) and (b) supercriticality ﹩\varepsilon ={ \mathcal R }-1﹩. Points represent results from 3D simulations, while curves show predictions from the BGS13 model, with color corresponding to the value of Pr; throughout, we fix τ = Pr/2 (Sc = 2). Vertical lines in panel (b) indicate the Ledoux threshold for convective instability for τ = 0.05 (blue) and τ = 0.005 (purple). Across all values of Pr considered, the BGS13 model remains in good agreement with simulations. Additionally, the data collapse more uniformly when plotted against ε than they do when plotted against r, indicating the former may be a more practical control parameter when studying thermohaline convection at small Pr and τ.