I find that very difficult to believe.
Berkey doesn’t last that long and they are UNESCO approved for relief in disasters and third world.
I personally use the Lifesaver Bottle. It will deliver pure water for as much as 6,000 liters before needing replacement.
$200
What price do you want to pay for water that won’t make you sick?
Thanks for the Lifesaver mention. Might get a bottle for a bug-out bag and a jerry can for the house.