The silver particles size is very important in colloidal silver. The smaller the particles, the more surface area it will cover. To put this in perspective, one ppm is equivalent to 1 milligram of something per liter of liquid (mg/l). So, if you have a 1 milligram (mg) particle or 1 thousand particles at 1 microgram (µg) (or 1/1000mg) each, in one liter of water, the silver content would be 1 ppm in both solutions. The second colloidal silver solution will be more effective because it will be able to attack one thousand pathogens compare to just one.
The importance of colloid particle surface area cannot be overemphasized. It is the single most important attribute for determining how effectively the colloidal particles will interact with their environment inside the human body.