LariAnn, I read the article in Forbes that is linked at the end of your article and it seemed to suggest that ionic silver worked best against microbes due to the activity of the ions combining with the proteins on the surface of the microbes. So now I'm a bit confused as to which form I should try for soaking seeds.
Also, Purest Colloids has a product they say is for hot tub use and not for internal human use. They don't say what the concentration is but just call it "concentrated" and I was wondering if that would be ok for horticultural use. It could probably be diluted and would, therefore, be very economical.
I've used the colloidal type but also have and use the ionic type. For horticultural purposes, either one should work well. The hot tub use product would seem to be OK for horticultural use; I got the regular colloidal silver because I wanted the option of using it on myself as well.
I haven't run a strict scientific study but have observed seedling survivability without vs. with the products. No question about the fact that, for me, the survivability of seedlings is enhanced with colloidal silver to keep pathogens at bay. Without it, I've lost as much as 100% of a seedling batch. With it, I've saved up to 100%.