Adele ring. In mathematics, the adele ring (also adelic ring or ring of adeles) is defined in class field theory, a branch of algebraic number theory. It allows one to elegantly describe the Artin reciprocity law. The adele ring is a self-dual topological ring, which is built on a global field.
Real softeners generally last 20+ years EVEN on ludicrously hard water while the service life on a pre-built softener seems to be under 5 years (if you're lucky) on really hard water and lasting longer than that is a rare exception.
You would not believe how much Culligan, Water Depot, Ecowater and all other big name companies mark up their prices on their water softeners. Not to mention their warranties are very limited and usually in the 1 to 5 year range.