To add to the confusion Porter's Camera Store In Idaho I think sells a unit that consist of a step down converter and a plastic covered device that leeches the silver out of solution by electrolysis. When the unit that is submerged in the tray becomes thoroughly covered you place the device in a plastic bag and ship it back to the manufacturer. They will weigh the silver and send you a check. You can then order another unit from Porter's. I think I bought the unit and one replacement unit for about
$40.00 or there abouts. Since I usually use all my chemicals one shot the units last a long time. .02 for what is worth.