A natural way to kill bacteria, fungus, yeast, molds, and viruses. Our product at 20ppm can be as effective as other brands at 500ppm or more. This is due to our smaller nano sized particles. The ppm measurement is weight based so having a silver with particles as low as 0.8nm would have 1000 times more bacterial killing action as a silver that has particles at 0.8microns. A nm is 1000 times smaller than a micron. A virus is between 4 and 100nm big and bacteria are between 1 and 10 microns so our silver has particles many times smaller than even the smallest microbe and much smaller than most competing colloidal silver brands.