Thermosolutal convection driven by opposed thermal and solutal buoyancy forces is experimentally investigated, by employing an electrochemical system in a low aspect ratio enclosure. In certain parametric ranges, it is observed that both the current and the temperature fluctuate. Criteria associated with the solutal Grashof number, and buoyancy and aspect ratios have been correlated to classify the characteristics of mass and heat transfer processes and various flow regimes, and a new length scale is suggested. The unsteady transport phenomena are found to depend on the Lewis number, Grashof number, and buoyancy and aspect ratios.