The slingshot is about 1,000 british pounds. For all its technology, that is really high. I work with engineers without borders and my team has gone the opposit

The slingshot is about 1,000 british pounds. For all its technology, that is really high. I work with engineers without borders and my team has gone the opposite route. Some water purification for all is better than perfect water purification for few. Our water purifier is basically a giant Brita filter. A concrete form for a tank, about a meter of sand, a plastic top, some piping, and you can have decent water purification for under $200 per village. The slingshot is technically superior but economically unfeasible.