re: #5 RanchTooth

As long as it’s waste or otherwise non-potable water, there shouldn’t be a problem.

I was thinking about this more. This is completely wrong. The initial reaction of splitting water into Hydrogen and Oxygen gases is done by sending an electric current through water, separating the atoms into their charged species, and having a positive (anode) and negative (cathode) pole in the solution. Hydrogen ions are positively charged, oxygen negatively charged, so you can guess which ion goes to what charged pole. The point is, the water would have to be SUPER PURIFIED to not have any competition from any other positively charged species in the water. Off the top of my head, the addition of NaCl (or normal table salt) in that same solution, would compete with the formation of oxygen gas to form chlorine gas, which is NOT A GOOD THING. I could go on, but, to be brief, it is not as simple as it sounds. The treatment of the water is another added cost to reduce wear and tear of parts of the apparatus.