Uh-oh. I did talk to a health food store years ago about silver colloid. This one was based in Boulder, which has a School of Mines where they had various commercial-grade silver colloid products tested. I probably brought this up as lower grade silver wires I have used to make silver colloid for myself cause tinnitus. Anyway, they said that many of the commercial silver colloid products they tested had heavy metal contaminants. I can only suggest making your own with three 9 volt batteries interconnected--you can invert and jam the tops to each other if the brand of battery is the right size--and get your silver wire from CC Silver & Gold out of Phoenix, Arizona. Just ask them for a quote for 12" of 9999 grade 12 or 14 gauge FINE SILVER WIRE. Then pay promptly as the price could go up. Cut the 12" wire in half, attach the ends of the two pieces to the plus and minus of your three linked 9 volt batteries or get three radio shack clips attached red-to-black. Stick the wires in a strip of wood 1/4" apart with tips showing to hook to batteries, parallel and not touching and insert the lower portion in distilled or demineralized water until clouds of silver come off into the water. Use that. Nickel is toxic. Check out all the multivitamin & mineral supplements that show NICKEL on their label! It's a stunner. God help us...