The Badeschiff, a floating swimming pool in Berlin. It opened in the summer of 2004 as an art project organized by the Stadtkunstprojekte (City Art Project Society) of Berlin. It was created by local artist, Susanne Lorenz, to enliven city life along a long-neglected stretch of the Spree.
I would love to have a natural shipping container pool where we don't have to use chemicals or salt to keep the water clean. Plants like these do the trick. You only have to keep the water constantly circulating.