The YTube vid: DIY CS generator, using a potentiometer, that Griz posted, shows how for a reasonable amount you can make your own CS and you will be more sure of the silver ion particle size you are getting (because with CS, size does matter, and with retail we are relying on hoping the silver particles are small enough to be effective). https://www.youtube.com/watch?v=KgAgsS5h8is