Positive versus negative flux. The top and bottom rows illustrate the radial mass flux (F_r, in units of ℳ/t_dyn) from inflowing and outflowing regions, respectively, for streams (left panels), non-streams (middle panels), and the total cold gas (right panels), plotted as a function of radius, r, normalized by R_d. Solid lines represent the median values across the disk galaxy sample, and shaded regions correspond to the 16^th–84^th percentile ranges. Results from the metallicity- and streamline-based classifications are shown in blue and green, respectively. In the streamline-based selection, inflowing and outflowing fluxes from non-stream gas are nearly equal in magnitude, comparable also to the inflowing stream flux, and largely cancel each other out. This leads to a total non-stream flux that is close to zero at the median level, though it exhibits significant scatter. A similar cancellation is also observed in the metallicity-based selection, where inflowing and outflowing non-stream fluxes are also comparable but individually much smaller than the stream flux, except at small radii (r ≲ 0.5 R_d), where the stream flux diminishes. As a result, the total non-stream flux in the metallicity-based selection also approaches zero, but with minimal scatter.