My Two Cents is That Home Units Don't Come Close
My two cents is that Mesosilver and
Utopia-Silver 's Advanced
Colloidal Silver (which I prefer) are the best true
Colloidal Silver products to be found anywhere on the planet.
I have written and researched about colloidal and ionic silver extensively and I have seen lab test results as well as actual production facilities and nothing else comes remotely close - and that certainly includes every DIY silver solution I have ever seen or heard about.
Nothing you find in home units has underwater, ultra high voltage, reversing polarity, plasma beam technology like those two do.
It all comes down to particle size and the ratio of
Colloidal Silver to ionic silver. Nothing made at home can produce particle sizes whose width is merely two and one half times that of a single silver atom - like those two aforementioned products. The smaller the particle, the more coverage per PPM.
Think of how many BB's you can get into a 50 gallon drum and their total surface area compared to the number of volley balls. And those small particles can go where the big ones can't - such as crossing over the blood-brain barrier.
When it comes to "freshness", the product I prefer and use exclusively is usually only days old - though I have seen and used some that was over two years old and it still worked wonderfully.