Harbor Freight has the best costs for modest treated steel stockpots that I've discovered, a lot of 4 for around 20 bucks.
I'm keen on sifting my water for drinking, yet I have an old black-top rooftop.
I don't know whether it's more terrible than the chlorinated and fluoridated city water, but at the same time I don't know a Berkey could sift through the petrochemical draining, surmise that would merit investigating.
Another steel rooftop on my home would be incredible, however a 10x10 water gathering haven may really be attainable .
A regular entire house channel could be plumbed to serve a committed drinking/cooking water line.
Given the moderately low day by day use, it should keep going quite a while.
