Abstract: The present invention is a method for producing hydrogen and oxygen from salt water, using an electrolyser having first and second electrode compartments respectively on each side of a hydrophilic ion-exchange membrane, the method comprising adding salt water to one or both of the electrode compartments, and electrolysing the salt water. The present invention is also a method of producing a biologically active solution using an electrolyser as defined above, the method comprising adding salt water to one or both of the electrode compartments, and electrolysing the salt water. Further, the present invention is a method for reducing the salt content of salt water using an electrolyser as defined above, the method comprising adding salt water to one or both electrode compartments, and electrolysing the salt water.