A method for generating a hydride gas of metal M1 in an electrochemical cell comprising a cathode comprising metal M1, a sacrificial anode comprising metal M2, an initial concentration of aqueous electrolyte solution comprising a metal hydroxide, M3OH, wherein the sacrificial metal anode electrochemically oxidizes in the presence of the aqueous electrolyte solution comprising M3OH to form a metal salt, and the hydride gas of metal M1 is formed by reducing the metal M1 of the cathode. The method comprises the steps of determining solubility profile curves of the metal salt as the M3OH is consumed and the metal oxide is formed by the oxidation reaction at various concentrations of M3OH; determining a maximum concentration of M3OH that, as it is consumed, does not yield a concentration of metal salt that precipitates out of the electrolyte solution; and choosing a concentration of M3OH that is in the range of at and within 5% less than the maximum concentration of M3OH to be the initial concentration of M3OH.