A previously described method for quantifying uptake of dilute photographic developer solutions (Dasgupta et al., Int J Heat Mass Transfer 1995;38:2029-37) [1] was applied to the floor of a recirculating flow tank near a submerged parallelepiped. The method was calibrated for a new combination of film and developer. Unlike [1], we found it preferable to include an autocatalytic term in the rate equation for silver development to adequately describe the kinetics of development. A map of mass transfer resistance between the bulk fluid and the flow tank floor was generated for future comparison to CFD predictions.