ie, 500ppm = 500mg of silver per/Liter of solution. To which I'd add, is not physically possible without additives(due to saturation limits). And so, right off the bat, we're left with an issue with regards to the claim that the solution is made of distilled water and silver(1)
Second obvious issue with this is where most all forms of silver compound(soluble or otherwise) measuring beyond 15ppm will promote color change(plasmon effect) in the solution.
And so the notion that we'd have 500ppm of silver in a clear solution pretty much says it all.
Hope this helps
PS. $105.00 for 240ml of Colloidal Silver is nothing short of a sin.
To which I'd add, I'll never get passed how sellers take horrible advantage of people when it comes to alternative health products. - terrible shame