In the other thread, someone mentioned this RO unit with 95% recovery:

https://hanspremiumwater.com/reverse-osmosis/

Mention: https://news.ycombinator.com/item?id=36662101

And

> You can dramatically increase efficiency by adding a permeate pump, search Amazon, they can be had very cheaply, they recycle the concentrate, increasing recovery and filter effectiveness.

https://news.ycombinator.com/item?id=36662141