A long-standing question in the dynamics of oceanic surface mixed layers (SML) is whether or not turbulence inhibits the rate of sedimentation through the layer. Results from previous studies have shown that turbulence can both retard and accelerate particle settling. Here we attempt to resolve this issue by demonstrating how both results can in fact be obtained from the same turbulence model for only slightly different implementations of the experimental set-up. Increasing turbulence will produce an increase in particle sedimentation if the SML is modelled as a homogeneous layer with a constant turbulent intensity throughout. However, if a more realistic representation of the SML is used, in which the turbulent intensity is allowed to decrease toward the base of the SML, then an increase in turbulence will lead to an increase in the residence time of particles in the SML.